diff --git a/src/metric-spaces.lagda.md b/src/metric-spaces.lagda.md
index bc48c2ee7e..2295e66fa9 100644
--- a/src/metric-spaces.lagda.md
+++ b/src/metric-spaces.lagda.md
@@ -57,6 +57,9 @@ metric space, `N d₂ x y` [or](foundation.disjunction.md)
module metric-spaces where
open import metric-spaces.accumulation-points-subsets-located-metric-spaces public
+open import metric-spaces.action-on-cauchy-approximations-isometries-pseudometric-spaces public
+open import metric-spaces.action-on-cauchy-approximations-short-maps-metric-spaces public
+open import metric-spaces.action-on-cauchy-approximations-short-maps-pseudometric-spaces public
open import metric-spaces.apartness-located-metric-spaces public
open import metric-spaces.approximations-located-metric-spaces public
open import metric-spaces.approximations-metric-spaces public
@@ -64,9 +67,11 @@ open import metric-spaces.bounded-distance-decompositions-of-metric-spaces publi
open import metric-spaces.cartesian-products-metric-spaces public
open import metric-spaces.category-of-metric-spaces-and-isometries public
open import metric-spaces.category-of-metric-spaces-and-short-functions public
+open import metric-spaces.cauchy-approximations-in-cauchy-pseudocompletions-of-pseudometric-spaces public
open import metric-spaces.cauchy-approximations-metric-quotients-of-pseudometric-spaces public
open import metric-spaces.cauchy-approximations-metric-spaces public
open import metric-spaces.cauchy-approximations-pseudometric-spaces public
+open import metric-spaces.cauchy-pseudocompletion-of-complete-metric-spaces public
open import metric-spaces.cauchy-pseudocompletion-of-metric-spaces public
open import metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces public
open import metric-spaces.cauchy-sequences-complete-metric-spaces public
diff --git a/src/metric-spaces/accumulation-points-subsets-located-metric-spaces.lagda.md b/src/metric-spaces/accumulation-points-subsets-located-metric-spaces.lagda.md
index 8f84ddb509..017333c0bc 100644
--- a/src/metric-spaces/accumulation-points-subsets-located-metric-spaces.lagda.md
+++ b/src/metric-spaces/accumulation-points-subsets-located-metric-spaces.lagda.md
@@ -28,6 +28,7 @@ open import lists.sequences
open import logic.functoriality-existential-quantification
+open import metric-spaces.action-on-cauchy-approximations-short-maps-metric-spaces
open import metric-spaces.apartness-located-metric-spaces
open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.cauchy-sequences-metric-spaces
@@ -80,7 +81,7 @@ module _
( x)) ∧
is-limit-cauchy-approximation-prop-Metric-Space
( metric-space-Located-Metric-Space X)
- ( map-short-function-cauchy-approximation-Metric-Space
+ ( map-cauchy-approximation-short-function-Metric-Space
( subspace-Located-Metric-Space X S)
( metric-space-Located-Metric-Space X)
( short-inclusion-subspace-Metric-Space
@@ -155,7 +156,7 @@ module _
( x)
( saturated-is-limit-cauchy-approximation-Metric-Space
( metric-space-Located-Metric-Space X)
- ( map-short-function-cauchy-approximation-Metric-Space
+ ( map-cauchy-approximation-short-function-Metric-Space
( subspace-Located-Metric-Space
( X)
( subset-closed-subset-Located-Metric-Space X S))
@@ -230,7 +231,7 @@ module _
( ( λ n → a#x _) ,
is-limit-cauchy-sequence-cauchy-approximation-Metric-Space
( metric-space-Located-Metric-Space X)
- ( map-short-function-cauchy-approximation-Metric-Space
+ ( map-cauchy-approximation-short-function-Metric-Space
( subspace-Located-Metric-Space X S)
( metric-space-Located-Metric-Space X)
( short-inclusion-subspace-Metric-Space
diff --git a/src/metric-spaces/action-on-cauchy-approximations-isometries-pseudometric-spaces.lagda.md b/src/metric-spaces/action-on-cauchy-approximations-isometries-pseudometric-spaces.lagda.md
new file mode 100644
index 0000000000..d4c567f6d3
--- /dev/null
+++ b/src/metric-spaces/action-on-cauchy-approximations-isometries-pseudometric-spaces.lagda.md
@@ -0,0 +1,143 @@
+# The action on Cauchy approximations of isometries between pseudometric spaces
+
+```agda
+module metric-spaces.action-on-cauchy-approximations-isometries-pseudometric-spaces where
+```
+
+Imports
+
+```agda
+open import elementary-number-theory.addition-positive-rational-numbers
+open import elementary-number-theory.positive-rational-numbers
+
+open import foundation.dependent-pair-types
+open import foundation.function-extensionality
+open import foundation.function-types
+open import foundation.homotopies
+open import foundation.identity-types
+open import foundation.propositions
+open import foundation.subtypes
+open import foundation.universe-levels
+
+open import metric-spaces.action-on-cauchy-approximations-short-maps-pseudometric-spaces
+open import metric-spaces.cauchy-approximations-pseudometric-spaces
+open import metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces
+open import metric-spaces.isometries-pseudometric-spaces
+open import metric-spaces.pseudometric-spaces
+open import metric-spaces.short-functions-pseudometric-spaces
+```
+
+
+
+## Idea
+
+[Isometries](metric-spaces.isometries-pseudometric-spaces.md) between
+[pseudometric spaces](metric-spaces.pseudometric-spaces.md) act on
+[Cauchy approximations](metric-spaces.cauchy-approximations-pseudometric-spaces.md)
+and induce an isometry between the
+[Cauchy pseudocompletions](metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces.md).
+
+## Definitions
+
+### The action of isometries on Cauchy approximations
+
+```agda
+module _
+ {l1 l2 l1' l2' : Level}
+ (A : Pseudometric-Space l1 l2) (B : Pseudometric-Space l1' l2')
+ (f : isometry-Pseudometric-Space A B)
+ where
+
+ map-cauchy-approximation-isometry-Pseudometric-Space :
+ cauchy-approximation-Pseudometric-Space A →
+ cauchy-approximation-Pseudometric-Space B
+ map-cauchy-approximation-isometry-Pseudometric-Space =
+ map-cauchy-approximation-short-function-Pseudometric-Space
+ ( A)
+ ( B)
+ ( short-isometry-Pseudometric-Space A B f)
+```
+
+## Properties
+
+### The action of isometries on Cauchy approximations is an isometry
+
+```agda
+module _
+ {l1 l2 l1' l2' : Level}
+ (A : Pseudometric-Space l1 l2) (B : Pseudometric-Space l1' l2')
+ (f : isometry-Pseudometric-Space A B)
+ where abstract
+
+ preserves-neighborhoods-map-cauchy-approximation-isometry-Pseudometric-Space :
+ (d : ℚ⁺) →
+ (x y : cauchy-approximation-Pseudometric-Space A) →
+ neighborhood-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space A)
+ ( d)
+ ( x)
+ ( y) →
+ neighborhood-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space B)
+ ( d)
+ ( map-cauchy-approximation-isometry-Pseudometric-Space A B f x)
+ ( map-cauchy-approximation-isometry-Pseudometric-Space A B f y)
+ preserves-neighborhoods-map-cauchy-approximation-isometry-Pseudometric-Space =
+ preserves-neighborhoods-map-cauchy-approximation-short-function-Pseudometric-Space
+ ( A)
+ ( B)
+ ( short-isometry-Pseudometric-Space A B f)
+
+ reflects-neighborhoods-map-cauchy-approximation-isometry-Pseudometric-Space :
+ (d : ℚ⁺) →
+ (x y : cauchy-approximation-Pseudometric-Space A) →
+ neighborhood-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space B)
+ ( d)
+ ( map-cauchy-approximation-isometry-Pseudometric-Space A B f x)
+ ( map-cauchy-approximation-isometry-Pseudometric-Space A B f y) →
+ neighborhood-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space A)
+ ( d)
+ ( x)
+ ( y)
+ reflects-neighborhoods-map-cauchy-approximation-isometry-Pseudometric-Space
+ d x y Nxy α β =
+ reflects-neighborhoods-map-isometry-Pseudometric-Space
+ ( A)
+ ( B)
+ ( f)
+ ( α +ℚ⁺ β +ℚ⁺ d)
+ ( map-cauchy-approximation-Pseudometric-Space A x α)
+ ( map-cauchy-approximation-Pseudometric-Space A y β)
+ ( Nxy α β)
+
+ is-isometry-map-cauchy-approximation-isometry-Pseudometric-Space :
+ is-isometry-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space A)
+ ( cauchy-pseudocompletion-Pseudometric-Space B)
+ ( map-cauchy-approximation-isometry-Pseudometric-Space A B f)
+ is-isometry-map-cauchy-approximation-isometry-Pseudometric-Space d x y =
+ ( ( preserves-neighborhoods-map-cauchy-approximation-isometry-Pseudometric-Space
+ ( d)
+ ( x)
+ ( y)) ,
+ ( reflects-neighborhoods-map-cauchy-approximation-isometry-Pseudometric-Space
+ ( d)
+ ( x)
+ ( y)))
+
+module _
+ {l1 l2 l1' l2' : Level}
+ (A : Pseudometric-Space l1 l2) (B : Pseudometric-Space l1' l2')
+ (f : isometry-Pseudometric-Space A B)
+ where
+
+ isometry-map-cauchy-approximation-isometry-Pseudometric-Space :
+ isometry-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space A)
+ ( cauchy-pseudocompletion-Pseudometric-Space B)
+ isometry-map-cauchy-approximation-isometry-Pseudometric-Space =
+ ( map-cauchy-approximation-isometry-Pseudometric-Space A B f ,
+ is-isometry-map-cauchy-approximation-isometry-Pseudometric-Space A B f)
+```
diff --git a/src/metric-spaces/action-on-cauchy-approximations-short-maps-metric-spaces.lagda.md b/src/metric-spaces/action-on-cauchy-approximations-short-maps-metric-spaces.lagda.md
new file mode 100644
index 0000000000..a4f3e6afe9
--- /dev/null
+++ b/src/metric-spaces/action-on-cauchy-approximations-short-maps-metric-spaces.lagda.md
@@ -0,0 +1,146 @@
+# The action on Cauchy approximations of short maps between metric spaces
+
+```agda
+module metric-spaces.action-on-cauchy-approximations-short-maps-metric-spaces where
+```
+
+Imports
+
+```agda
+open import elementary-number-theory.addition-positive-rational-numbers
+open import elementary-number-theory.positive-rational-numbers
+
+open import foundation.dependent-pair-types
+open import foundation.function-extensionality
+open import foundation.function-types
+open import foundation.homotopies
+open import foundation.identity-types
+open import foundation.propositions
+open import foundation.subtypes
+open import foundation.universe-levels
+
+open import metric-spaces.action-on-cauchy-approximations-short-maps-pseudometric-spaces
+open import metric-spaces.cauchy-approximations-metric-spaces
+open import metric-spaces.cauchy-pseudocompletion-of-metric-spaces
+open import metric-spaces.limits-of-cauchy-approximations-metric-spaces
+open import metric-spaces.metric-spaces
+open import metric-spaces.short-functions-metric-spaces
+open import metric-spaces.short-functions-pseudometric-spaces
+```
+
+
+
+## Idea
+
+[Short maps](metric-spaces.short-functions-metric-spaces.md) between
+[metric spaces](metric-spaces.metric-spaces.md) act on
+[cauchy approximations](metric-spaces.cauchy-approximations-metric-spaces.md)
+and induce a short map between the
+[Cauchy pseudocompletions](metric-spaces.cauchy-pseudocompletion-of-metric-spaces.md).
+
+This action is functorial and preserves
+[limits](metric-spaces.limits-of-cauchy-approximations-metric-spaces.md).
+
+## Definitions
+
+### The action of short maps on Cauchy approximations
+
+```agda
+module _
+ {l1 l2 l1' l2' : Level}
+ (A : Metric-Space l1 l2) (B : Metric-Space l1' l2')
+ (f : short-function-Metric-Space A B)
+ where
+
+ short-map-cauchy-pseudocompletion-short-function-Metric-Space :
+ short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space A)
+ ( cauchy-pseudocompletion-Metric-Space B)
+ short-map-cauchy-pseudocompletion-short-function-Metric-Space =
+ short-map-cauchy-approximation-short-function-Pseudometric-Space
+ ( pseudometric-Metric-Space A)
+ ( pseudometric-Metric-Space B)
+ ( f)
+
+ map-cauchy-approximation-short-function-Metric-Space :
+ cauchy-approximation-Metric-Space A →
+ cauchy-approximation-Metric-Space B
+ map-cauchy-approximation-short-function-Metric-Space =
+ map-short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space A)
+ ( cauchy-pseudocompletion-Metric-Space B)
+ ( short-map-cauchy-pseudocompletion-short-function-Metric-Space)
+
+ preserves-neighborhoods-map-cauchy-approximation-short-function-Metric-Space :
+ is-short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space A)
+ ( cauchy-pseudocompletion-Metric-Space B)
+ ( map-cauchy-approximation-short-function-Metric-Space)
+ preserves-neighborhoods-map-cauchy-approximation-short-function-Metric-Space =
+ is-short-map-short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space A)
+ ( cauchy-pseudocompletion-Metric-Space B)
+ ( short-map-cauchy-pseudocompletion-short-function-Metric-Space)
+```
+
+## Properties
+
+### Functoriality of the action of short maps
+
+```agda
+module _
+ {l1 l2 : Level}
+ (A : Metric-Space l1 l2)
+ where abstract
+
+ htpy-id-map-cauchy-approximation-short-function-Metric-Space :
+ map-cauchy-approximation-short-function-Metric-Space
+ ( A)
+ ( A)
+ ( id-short-function-Metric-Space A) =
+ id
+ htpy-id-map-cauchy-approximation-short-function-Metric-Space = refl
+
+module _
+ {l1a l2a l1b l2b l1c l2c : Level}
+ (A : Metric-Space l1a l2a)
+ (B : Metric-Space l1b l2b)
+ (C : Metric-Space l1c l2c)
+ (g : short-function-Metric-Space B C)
+ (f : short-function-Metric-Space A B)
+ where abstract
+
+ htpy-comp-map-cauchy-approximation-short-function-Metric-Space :
+ ( map-cauchy-approximation-short-function-Metric-Space B C g ∘
+ map-cauchy-approximation-short-function-Metric-Space A B f) =
+ ( map-cauchy-approximation-short-function-Metric-Space A C
+ ( comp-short-function-Metric-Space A B C g f))
+ htpy-comp-map-cauchy-approximation-short-function-Metric-Space = refl
+```
+
+### The action of short maps on Cauchy approximations preserves limits
+
+```agda
+module _
+ {l1 l2 l1' l2' : Level}
+ (A : Metric-Space l1 l2) (B : Metric-Space l1' l2')
+ (f : short-function-Metric-Space A B)
+ (a : cauchy-approximation-Metric-Space A)
+ (lim : type-Metric-Space A)
+ where abstract
+
+ preserves-limit-map-cauchy-approximation-short-function-Metric-Space :
+ is-limit-cauchy-approximation-Metric-Space A a lim →
+ is-limit-cauchy-approximation-Metric-Space
+ ( B)
+ ( map-cauchy-approximation-short-function-Metric-Space A B f a)
+ ( map-short-function-Metric-Space A B f lim)
+ preserves-limit-map-cauchy-approximation-short-function-Metric-Space
+ is-lim-a ε δ =
+ is-short-map-short-function-Metric-Space A B
+ ( f)
+ ( ε +ℚ⁺ δ)
+ ( map-cauchy-approximation-Metric-Space A a ε)
+ ( lim)
+ ( is-lim-a ε δ)
+```
diff --git a/src/metric-spaces/action-on-cauchy-approximations-short-maps-pseudometric-spaces.lagda.md b/src/metric-spaces/action-on-cauchy-approximations-short-maps-pseudometric-spaces.lagda.md
new file mode 100644
index 0000000000..fae98702b5
--- /dev/null
+++ b/src/metric-spaces/action-on-cauchy-approximations-short-maps-pseudometric-spaces.lagda.md
@@ -0,0 +1,98 @@
+# The action on Cauchy approximations of short maps between pseudometric spaces
+
+```agda
+module metric-spaces.action-on-cauchy-approximations-short-maps-pseudometric-spaces where
+```
+
+Imports
+
+```agda
+open import elementary-number-theory.addition-positive-rational-numbers
+open import elementary-number-theory.positive-rational-numbers
+
+open import foundation.dependent-pair-types
+open import foundation.function-extensionality
+open import foundation.function-types
+open import foundation.homotopies
+open import foundation.identity-types
+open import foundation.propositions
+open import foundation.subtypes
+open import foundation.universe-levels
+
+open import metric-spaces.cauchy-approximations-pseudometric-spaces
+open import metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces
+open import metric-spaces.isometries-pseudometric-spaces
+open import metric-spaces.pseudometric-spaces
+open import metric-spaces.short-functions-pseudometric-spaces
+```
+
+
+
+## Idea
+
+[Short maps](metric-spaces.short-functions-pseudometric-spaces.md) between
+[pseudometric spaces](metric-spaces.pseudometric-spaces.md) act on
+[cauchy approximations](metric-spaces.cauchy-approximations-pseudometric-spaces.md)
+and induce a short map between the
+[Cauchy pseudocompletions](metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces.md).
+
+## Definitions
+
+### The action of short maps on Cauchy approximations
+
+```agda
+module _
+ {l1 l2 l1' l2' : Level}
+ (A : Pseudometric-Space l1 l2) (B : Pseudometric-Space l1' l2')
+ (f : short-function-Pseudometric-Space A B)
+ where
+
+ map-cauchy-approximation-short-function-Pseudometric-Space :
+ cauchy-approximation-Pseudometric-Space A →
+ cauchy-approximation-Pseudometric-Space B
+ map-cauchy-approximation-short-function-Pseudometric-Space (u , H) =
+ ( map-short-function-Pseudometric-Space A B f ∘ u ,
+ λ ε δ →
+ is-short-map-short-function-Pseudometric-Space
+ ( A)
+ ( B)
+ ( f)
+ ( ε +ℚ⁺ δ)
+ ( u ε)
+ ( u δ)
+ ( H ε δ))
+```
+
+## Properties
+
+### The action of short maps on Cauchy approximations is short
+
+```agda
+module _
+ {l1 l2 l1' l2' : Level}
+ (A : Pseudometric-Space l1 l2) (B : Pseudometric-Space l1' l2')
+ (f : short-function-Pseudometric-Space A B)
+ where
+
+ abstract
+ preserves-neighborhoods-map-cauchy-approximation-short-function-Pseudometric-Space :
+ is-short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space A)
+ ( cauchy-pseudocompletion-Pseudometric-Space B)
+ ( map-cauchy-approximation-short-function-Pseudometric-Space A B f)
+ preserves-neighborhoods-map-cauchy-approximation-short-function-Pseudometric-Space
+ d x y Nxy α β =
+ is-short-map-short-function-Pseudometric-Space A B f
+ ( α +ℚ⁺ β +ℚ⁺ d)
+ ( map-cauchy-approximation-Pseudometric-Space A x α)
+ ( map-cauchy-approximation-Pseudometric-Space A y β)
+ ( Nxy α β)
+
+ short-map-cauchy-approximation-short-function-Pseudometric-Space :
+ short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space A)
+ ( cauchy-pseudocompletion-Pseudometric-Space B)
+ short-map-cauchy-approximation-short-function-Pseudometric-Space =
+ ( map-cauchy-approximation-short-function-Pseudometric-Space A B f ,
+ preserves-neighborhoods-map-cauchy-approximation-short-function-Pseudometric-Space)
+```
diff --git a/src/metric-spaces/bounded-distance-decompositions-of-metric-spaces.lagda.md b/src/metric-spaces/bounded-distance-decompositions-of-metric-spaces.lagda.md
index ea2bf3aa07..006f92d5f2 100644
--- a/src/metric-spaces/bounded-distance-decompositions-of-metric-spaces.lagda.md
+++ b/src/metric-spaces/bounded-distance-decompositions-of-metric-spaces.lagda.md
@@ -33,6 +33,7 @@ open import foundation.subtypes
open import foundation.transport-along-identifications
open import foundation.universe-levels
+open import metric-spaces.action-on-cauchy-approximations-short-maps-metric-spaces
open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.elements-at-bounded-distance-metric-spaces
open import metric-spaces.equality-of-metric-spaces
@@ -213,7 +214,7 @@ module _
{l1 l2 : Level} (A : Metric-Space l1 l2)
where
- preserves-neighborhood-map-equiv-bounded-distance-decomposition-Metric-Space :
+ preserves-neighborhoods-map-equiv-bounded-distance-decomposition-Metric-Space :
( d : ℚ⁺)
( x y : type-bounded-distance-decomposition-Metric-Space A) →
neighborhood-Metric-Space
@@ -224,7 +225,7 @@ module _
neighborhood-Metric-Space A d
( map-equiv-bounded-distance-decomposition-Metric-Space A x)
( map-equiv-bounded-distance-decomposition-Metric-Space A y)
- preserves-neighborhood-map-equiv-bounded-distance-decomposition-Metric-Space
+ preserves-neighborhoods-map-equiv-bounded-distance-decomposition-Metric-Space
d (X , x , x∈X) (Y , y , y∈Y) (X=Y , Nxy) =
forward-implication
( lemma-iff-neighborhood-bounded-distance-decomposition-Metric-Space
@@ -237,7 +238,7 @@ module _
( y , y∈Y))
( Nxy)
- reflects-neighborhood-map-equiv-bounded-distance-decomposition-Metric-Space :
+ reflects-neighborhoods-map-equiv-bounded-distance-decomposition-Metric-Space :
( d : ℚ⁺)
( x y : type-bounded-distance-decomposition-Metric-Space A) →
neighborhood-Metric-Space A d
@@ -248,7 +249,7 @@ module _
( d)
( x)
( y)
- reflects-neighborhood-map-equiv-bounded-distance-decomposition-Metric-Space
+ reflects-neighborhoods-map-equiv-bounded-distance-decomposition-Metric-Space
d (X , x , x∈X) (Y , y , y∈Y) Nxy =
( lemma-eq ,
backward-implication
@@ -280,11 +281,11 @@ module _
( map-equiv-bounded-distance-decomposition-Metric-Space A)
is-isometry-map-equiv-bounded-distance-decomposition-Metric-Space
d x y =
- ( ( preserves-neighborhood-map-equiv-bounded-distance-decomposition-Metric-Space
+ ( ( preserves-neighborhoods-map-equiv-bounded-distance-decomposition-Metric-Space
( d)
( x)
( y)) ,
- ( reflects-neighborhood-map-equiv-bounded-distance-decomposition-Metric-Space
+ ( reflects-neighborhoods-map-equiv-bounded-distance-decomposition-Metric-Space
( d)
( x)
( y)))
@@ -342,7 +343,7 @@ module _
map-cauchy-approximation-subspace-bounded-distance-component-Metric-Space :
cauchy-approximation-Metric-Space A
map-cauchy-approximation-subspace-bounded-distance-component-Metric-Space =
- map-short-function-cauchy-approximation-Metric-Space
+ map-cauchy-approximation-short-function-Metric-Space
( subspace-bounded-distance-component-Metric-Space A X)
( A)
( short-inclusion-subspace-Metric-Space
diff --git a/src/metric-spaces/cauchy-approximations-in-cauchy-pseudocompletions-of-pseudometric-spaces.lagda.md b/src/metric-spaces/cauchy-approximations-in-cauchy-pseudocompletions-of-pseudometric-spaces.lagda.md
new file mode 100644
index 0000000000..d147667cda
--- /dev/null
+++ b/src/metric-spaces/cauchy-approximations-in-cauchy-pseudocompletions-of-pseudometric-spaces.lagda.md
@@ -0,0 +1,469 @@
+# Cauchy approximations in the Cauchy pseudocompletion of a pseudometric space
+
+```agda
+{-# OPTIONS --lossy-unification #-}
+
+module
+ metric-spaces.cauchy-approximations-in-cauchy-pseudocompletions-of-pseudometric-spaces
+ where
+```
+
+Imports
+
+```agda
+open import elementary-number-theory.addition-positive-rational-numbers
+open import elementary-number-theory.positive-rational-numbers
+open import elementary-number-theory.strict-inequality-positive-rational-numbers
+open import elementary-number-theory.strict-inequality-rational-numbers
+
+open import foundation.action-on-identifications-binary-functions
+open import foundation.action-on-identifications-functions
+open import foundation.binary-relations
+open import foundation.dependent-pair-types
+open import foundation.function-types
+open import foundation.identity-types
+open import foundation.propositions
+open import foundation.transport-along-identifications
+open import foundation.universe-levels
+
+open import metric-spaces.action-on-cauchy-approximations-isometries-pseudometric-spaces
+open import metric-spaces.action-on-cauchy-approximations-short-maps-pseudometric-spaces
+open import metric-spaces.cauchy-approximations-pseudometric-spaces
+open import metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces
+open import metric-spaces.isometries-pseudometric-spaces
+open import metric-spaces.limits-of-cauchy-approximations-pseudometric-spaces
+open import metric-spaces.pseudometric-spaces
+open import metric-spaces.rational-neighborhood-relations
+open import metric-spaces.short-functions-pseudometric-spaces
+open import metric-spaces.similarity-of-elements-pseudometric-spaces
+```
+
+
+
+## Idea
+
+[Cauchy approximations](metric-spaces.cauchy-approximations-pseudometric-spaces.md)
+in the
+[Cauchy pseudocompletion](metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces.md)
+of a [pseudometric space](metric-spaces.pseudometric-spaces.md) have a
+[limit](metric-spaces.limits-of-cauchy-approximations-pseudometric-spaces.md).
+
+## Properties
+
+### Any Cauchy approximation in the Cauchy pseudocompletion of a pseudometric space has a limit
+
+```agda
+module _
+ { l1 l2 : Level} (M : Pseudometric-Space l1 l2)
+ ( U :
+ cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ where
+
+ map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ ℚ⁺ → ℚ⁺ → type-Pseudometric-Space M
+ map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space ε =
+ map-cauchy-approximation-Pseudometric-Space M
+ ( map-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( U)
+ ( ε))
+
+ is-cauchy-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ (δ ε d₁ d₂ : ℚ⁺) →
+ neighborhood-Pseudometric-Space
+ ( M)
+ ( d₁ +ℚ⁺ d₂ +ℚ⁺ (δ +ℚ⁺ ε))
+ ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( δ)
+ ( d₁))
+ ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( ε)
+ ( d₂))
+ is-cauchy-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ =
+ is-cauchy-approximation-map-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( U)
+
+ map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ ℚ⁺ → type-Pseudometric-Space M
+ map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space d =
+ let
+ (d₁ , d₂ , _) = split-ℚ⁺ d
+ in
+ map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space d₂ d₁
+
+ abstract
+ is-cauchy-map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ is-cauchy-approximation-Pseudometric-Space
+ ( M)
+ ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
+ is-cauchy-map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ δ ε =
+ let
+ (δ₁ , δ₂ , δ₁+δ₂=δ) = split-ℚ⁺ δ
+ (ε₁ , ε₂ , ε₁+ε₂=ε) = split-ℚ⁺ ε
+
+ lemma-δ+ε :
+ ((δ₁ +ℚ⁺ ε₁) +ℚ⁺ (δ₂ +ℚ⁺ ε₂)) = δ +ℚ⁺ ε
+ lemma-δ+ε =
+ ( interchange-law-add-add-ℚ⁺ δ₁ ε₁ δ₂ ε₂) ∙
+ ( ap-binary add-ℚ⁺ δ₁+δ₂=δ ε₁+ε₂=ε)
+ in
+ tr
+ ( is-upper-bound-dist-Pseudometric-Space
+ ( M)
+ ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( δ))
+ ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( ε)))
+ ( lemma-δ+ε)
+ ( is-cauchy-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ _ _ _ _)
+
+ lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ cauchy-approximation-Pseudometric-Space M
+ lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space =
+ ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space ,
+ is-cauchy-map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
+
+ abstract
+ is-limit-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ is-limit-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( U)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
+ is-limit-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ δ ε η θ =
+ let
+ (θ₁ , θ₂ , θ₁+θ₂=θ) = split-ℚ⁺ θ
+
+ lemma-η+θ+δ :
+ ((η +ℚ⁺ θ₁) +ℚ⁺ (δ +ℚ⁺ θ₂)) = η +ℚ⁺ θ +ℚ⁺ δ
+ lemma-η+θ+δ =
+ ( interchange-law-add-add-ℚ⁺ η θ₁ δ θ₂) ∙
+ ( ap
+ ( add-ℚ⁺ (η +ℚ⁺ δ))
+ ( θ₁+θ₂=θ)) ∙
+ ( associative-add-ℚ⁺ η δ θ) ∙
+ ( ap
+ ( add-ℚ⁺ η)
+ ( commutative-add-ℚ⁺ δ θ)) ∙
+ ( inv (associative-add-ℚ⁺ η θ δ))
+
+ lemma-lim :
+ neighborhood-Pseudometric-Space M
+ ( η +ℚ⁺ θ +ℚ⁺ δ)
+ ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( δ)
+ ( η))
+ ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( θ₂)
+ ( θ₁))
+ lemma-lim =
+ tr
+ ( is-upper-bound-dist-Pseudometric-Space M
+ ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( δ)
+ ( η))
+ ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( θ)))
+ ( lemma-η+θ+δ)
+ ( is-cauchy-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ _ _ _ _)
+ in
+ tr
+ ( is-upper-bound-dist-Pseudometric-Space M
+ ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( δ)
+ ( η))
+ ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( θ)))
+ ( associative-add-ℚ⁺
+ ( η +ℚ⁺ θ)
+ ( δ)
+ ( ε))
+ ( monotonic-neighborhood-Pseudometric-Space M
+ ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( δ)
+ ( η))
+ ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( θ))
+ ( η +ℚ⁺ θ +ℚ⁺ δ)
+ ( η +ℚ⁺ θ +ℚ⁺ δ +ℚ⁺ ε)
+ ( le-left-add-ℚ⁺ ( η +ℚ⁺ θ +ℚ⁺ δ) ε)
+ ( lemma-lim))
+
+ has-limit-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ Σ ( cauchy-approximation-Pseudometric-Space M)
+ ( is-limit-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( U))
+ has-limit-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space =
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space ,
+ is-limit-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
+```
+
+### Any Cauchy approximation in the pseudometric completion is similar to the constant Cauchy approximation of its limit
+
+```agda
+module _
+ { l1 l2 : Level} (M : Pseudometric-Space l1 l2)
+ ( u :
+ cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ where
+
+ sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( u)
+ ( const-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u)))
+ sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ =
+ sim-const-is-limit-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( u)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M u)
+ ( is-limit-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u))
+```
+
+### The map from a Cauchy approximation in the pseudometric completion to its limit is short
+
+```agda
+module _
+ {l1 l2 : Level} (M : Pseudometric-Space l1 l2)
+ where
+
+ abstract
+ is-short-function-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ is-short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( ( const-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)) ∘
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)))
+ is-short-function-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ d u v =
+ preserves-neighborhoods-sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ { u}
+ { const-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u))}
+ { v}
+ { const-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( v))}
+ ( sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u))
+ ( sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( v))
+ ( d)
+
+ is-short-function-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space :
+ is-short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M)
+ is-short-function-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space
+ d u v Nuv =
+ reflects-neighborhoods-map-cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( d)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u))
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( v))
+ ( is-short-function-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( d)
+ ( u)
+ ( v)
+ ( Nuv))
+
+ short-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space :
+ short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ short-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space =
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M ,
+ is-short-function-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space)
+```
+
+### The map from a Cauchy approximation in the pseudometric completion to its limit is an isometry
+
+```agda
+module _
+ {l1 l2 : Level} (M : Pseudometric-Space l1 l2)
+ where
+
+ abstract
+ reflects-neighborhoods-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ ( d : ℚ⁺) →
+ ( u v :
+ cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)) →
+ neighborhood-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( d)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u))
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( v)) →
+ neighborhood-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( d)
+ ( u)
+ ( v)
+ reflects-neighborhoods-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ d u v N-lim =
+ reflects-neighborhoods-sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ { u}
+ { const-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u))}
+ { v}
+ { const-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( v))}
+ ( sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u))
+ ( sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( v))
+ ( d)
+ ( preserves-neighborhoods-map-cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( d)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( u))
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( v))
+ ( N-lim))
+
+ is-isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ is-isometry-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M)
+ is-isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ d x y =
+ ( ( is-short-function-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space
+ ( M)
+ ( d)
+ ( x)
+ ( y)) ,
+ ( reflects-neighborhoods-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
+ ( d)
+ ( x)
+ ( y)))
+
+ isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ isometry-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space =
+ ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M ,
+ is-isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
+```
+
+### The image of a Cauchy approximation in the Cauchy pseudocompletion is convergent
+
+```agda
+module _
+ {l1 l2 : Level} (M : Pseudometric-Space l1 l2)
+ (u : cauchy-approximation-Pseudometric-Space M)
+ where
+
+ is-limit-map-cauchy-approximation-cauchy-pseudocompletion-Ppseudometric-Space :
+ is-limit-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( map-cauchy-approximation-short-function-Pseudometric-Space
+ ( M)
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( short-map-cauchy-pseudocompletion-Pseudometric-Space M)
+ ( u))
+ ( u)
+ is-limit-map-cauchy-approximation-cauchy-pseudocompletion-Ppseudometric-Space
+ ε δ α β =
+ symmetric-neighborhood-Pseudometric-Space M
+ ( (α +ℚ⁺ β) +ℚ⁺ (ε +ℚ⁺ δ))
+ ( map-cauchy-approximation-Pseudometric-Space M u β)
+ ( map-cauchy-approximation-Pseudometric-Space M u ε)
+ ( monotonic-neighborhood-Pseudometric-Space M
+ ( map-cauchy-approximation-Pseudometric-Space M u β)
+ ( map-cauchy-approximation-Pseudometric-Space M u ε)
+ ( β +ℚ⁺ ε)
+ ( (α +ℚ⁺ β) +ℚ⁺ (ε +ℚ⁺ δ))
+ ( preserves-le-add-ℚ
+ { rational-ℚ⁺ β}
+ { rational-ℚ⁺ (α +ℚ⁺ β)}
+ { rational-ℚ⁺ ε}
+ { rational-ℚ⁺ (ε +ℚ⁺ δ)}
+ ( le-right-add-ℚ⁺ α β)
+ ( le-left-add-ℚ⁺ ε δ))
+ ( is-cauchy-approximation-map-cauchy-approximation-Pseudometric-Space
+ ( M)
+ ( u)
+ ( β)
+ ( ε)))
+
+ sim-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M))
+ ( map-cauchy-approximation-short-function-Pseudometric-Space
+ ( M)
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( short-map-cauchy-pseudocompletion-Pseudometric-Space M)
+ ( u))
+ ( map-cauchy-pseudocompletion-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( u))
+ sim-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space =
+ sim-const-is-limit-cauchy-approximation-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( map-cauchy-approximation-short-function-Pseudometric-Space
+ ( M)
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( short-map-cauchy-pseudocompletion-Pseudometric-Space M)
+ ( u))
+ ( u)
+ ( is-limit-map-cauchy-approximation-cauchy-pseudocompletion-Ppseudometric-Space)
+```
diff --git a/src/metric-spaces/cauchy-approximations-metric-quotients-of-pseudometric-spaces.lagda.md b/src/metric-spaces/cauchy-approximations-metric-quotients-of-pseudometric-spaces.lagda.md
index 9184f29af6..5945ef2dc0 100644
--- a/src/metric-spaces/cauchy-approximations-metric-quotients-of-pseudometric-spaces.lagda.md
+++ b/src/metric-spaces/cauchy-approximations-metric-quotients-of-pseudometric-spaces.lagda.md
@@ -42,6 +42,7 @@ open import foundation.universe-levels
open import logic.functoriality-existential-quantification
+open import metric-spaces.action-on-cauchy-approximations-short-maps-pseudometric-spaces
open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.cauchy-approximations-pseudometric-spaces
open import metric-spaces.cauchy-pseudocompletion-of-metric-spaces
@@ -101,40 +102,40 @@ module _
{l1 l2 : Level} (M : Pseudometric-Space l1 l2)
where
- short-map-metric-quotient-cauchy-apprtoximation-Pseudometric-Space :
+ short-map-cauchy-approximation-metric-quotient-Pseudometric-Space :
short-function-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space M)
( cauchy-pseudocompletion-Metric-Space
( metric-quotient-Pseudometric-Space M))
- short-map-metric-quotient-cauchy-apprtoximation-Pseudometric-Space =
- short-map-short-function-cauchy-approximation-Pseudometric-Space
+ short-map-cauchy-approximation-metric-quotient-Pseudometric-Space =
+ short-map-cauchy-approximation-short-function-Pseudometric-Space
( M)
( pseudometric-metric-quotient-Pseudometric-Space M)
( short-map-metric-quotient-Pseudometric-Space M)
- map-metric-quotient-cauchy-approximation-Pseudometric-Space :
+ map-cauchy-approximation-metric-quotient-Pseudometric-Space :
cauchy-approximation-Pseudometric-Space M →
cauchy-approximation-Metric-Space
( metric-quotient-Pseudometric-Space M)
- map-metric-quotient-cauchy-approximation-Pseudometric-Space =
+ map-cauchy-approximation-metric-quotient-Pseudometric-Space =
map-short-function-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space M)
( cauchy-pseudocompletion-Metric-Space
( metric-quotient-Pseudometric-Space M))
- ( short-map-metric-quotient-cauchy-apprtoximation-Pseudometric-Space)
+ ( short-map-cauchy-approximation-metric-quotient-Pseudometric-Space)
- is-short-map-metric-quotient-cauchy-approximation-Pseudometric-Space :
+ is-short-map-cauchy-approximation-metric-quotient-Pseudometric-Space :
is-short-function-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space M)
( cauchy-pseudocompletion-Metric-Space
( metric-quotient-Pseudometric-Space M))
- ( map-metric-quotient-cauchy-approximation-Pseudometric-Space)
- is-short-map-metric-quotient-cauchy-approximation-Pseudometric-Space =
+ ( map-cauchy-approximation-metric-quotient-Pseudometric-Space)
+ is-short-map-cauchy-approximation-metric-quotient-Pseudometric-Space =
is-short-map-short-function-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space M)
( cauchy-pseudocompletion-Metric-Space
( metric-quotient-Pseudometric-Space M))
- ( short-map-metric-quotient-cauchy-apprtoximation-Pseudometric-Space)
+ ( short-map-cauchy-approximation-metric-quotient-Pseudometric-Space)
```
### Lifts of Cauchy approximations in the quotient metric space up to similarity
@@ -155,7 +156,7 @@ module _
( cauchy-pseudocompletion-Pseudometric-Space
( pseudometric-metric-quotient-Pseudometric-Space A))
( u)
- ( map-metric-quotient-cauchy-approximation-Pseudometric-Space A v)
+ ( map-cauchy-approximation-metric-quotient-Pseudometric-Space A v)
is-lift-quotient-cauchy-approximation-Pseudometric-Space : UU (l1 ⊔ l2)
is-lift-quotient-cauchy-approximation-Pseudometric-Space =
@@ -206,12 +207,12 @@ module _
is-limit-cauchy-approximation-Pseudometric-Space M u lim)
where
- preserves-limits-map-metric-quotient-cauchy-approximation-Pseudometric-Space :
+ preserves-limits-map-cauchy-approximation-metric-quotient-Pseudometric-Space :
is-limit-cauchy-approximation-Metric-Space
( metric-quotient-Pseudometric-Space M)
- ( map-metric-quotient-cauchy-approximation-Pseudometric-Space M u)
+ ( map-cauchy-approximation-metric-quotient-Pseudometric-Space M u)
( map-metric-quotient-Pseudometric-Space M lim)
- preserves-limits-map-metric-quotient-cauchy-approximation-Pseudometric-Space
+ preserves-limits-map-cauchy-approximation-metric-quotient-Pseudometric-Space
ε δ (x , x∈uε) (y , y∈lim) =
let
lim~y : sim-Pseudometric-Space M lim y
@@ -233,7 +234,7 @@ module _
( x)
( x∈uε)
in
- preserves-neighborhood-sim-Pseudometric-Space
+ preserves-neighborhoods-sim-Pseudometric-Space
( M)
( uε~x)
( lim~y)
@@ -252,14 +253,14 @@ module _
has-lift-map-quotient-cauchy-approximation-metric-quotient-Pseudometric-Space :
has-lift-cauchy-approximation-metric-quotient-Pseudometric-Space
( A)
- ( map-metric-quotient-cauchy-approximation-Pseudometric-Space A u)
+ ( map-cauchy-approximation-metric-quotient-Pseudometric-Space A u)
has-lift-map-quotient-cauchy-approximation-metric-quotient-Pseudometric-Space =
unit-trunc-Prop
( u ,
refl-sim-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space
( pseudometric-metric-quotient-Pseudometric-Space A))
- ( map-metric-quotient-cauchy-approximation-Pseudometric-Space A u))
+ ( map-cauchy-approximation-metric-quotient-Pseudometric-Space A u))
```
### Convergent Cauchy approximations in the quotient metric space have a lift up to similarity
diff --git a/src/metric-spaces/cauchy-approximations-metric-spaces.lagda.md b/src/metric-spaces/cauchy-approximations-metric-spaces.lagda.md
index caf5ee3d31..b1fd39f15f 100644
--- a/src/metric-spaces/cauchy-approximations-metric-spaces.lagda.md
+++ b/src/metric-spaces/cauchy-approximations-metric-spaces.lagda.md
@@ -10,9 +10,6 @@ module metric-spaces.cauchy-approximations-metric-spaces where
open import elementary-number-theory.addition-positive-rational-numbers
open import elementary-number-theory.positive-rational-numbers
-open import foundation.constant-maps
-open import foundation.dependent-pair-types
-open import foundation.function-extensionality
open import foundation.function-types
open import foundation.homotopies
open import foundation.identity-types
@@ -20,7 +17,6 @@ open import foundation.propositions
open import foundation.subtypes
open import foundation.universe-levels
-open import metric-spaces.cartesian-products-metric-spaces
open import metric-spaces.cauchy-approximations-pseudometric-spaces
open import metric-spaces.metric-spaces
open import metric-spaces.short-functions-metric-spaces
@@ -110,54 +106,6 @@ module _
( x)
```
-### The action of short maps on Cauchy approximations
-
-```agda
-module _
- {l1 l2 l1' l2' : Level}
- (A : Metric-Space l1 l2) (B : Metric-Space l1' l2')
- (f : short-function-Metric-Space A B)
- where
-
- map-short-function-cauchy-approximation-Metric-Space :
- cauchy-approximation-Metric-Space A →
- cauchy-approximation-Metric-Space B
- map-short-function-cauchy-approximation-Metric-Space =
- map-short-function-cauchy-approximation-Pseudometric-Space
- ( pseudometric-Metric-Space A)
- ( pseudometric-Metric-Space B)
- ( f)
-
-module _
- {l1 l2 : Level}
- (A : Metric-Space l1 l2)
- where
-
- eq-id-map-short-function-cauchy-approximation-Metric-Space :
- map-short-function-cauchy-approximation-Metric-Space
- ( A)
- ( A)
- ( short-id-Metric-Space A) =
- id
- eq-id-map-short-function-cauchy-approximation-Metric-Space = refl
-
-module _
- {l1a l2a l1b l2b l1c l2c : Level}
- (A : Metric-Space l1a l2a)
- (B : Metric-Space l1b l2b)
- (C : Metric-Space l1c l2c)
- (g : short-function-Metric-Space B C)
- (f : short-function-Metric-Space A B)
- where
-
- eq-comp-map-short-function-cauchy-approximation-Metric-Space :
- ( map-short-function-cauchy-approximation-Metric-Space B C g ∘
- map-short-function-cauchy-approximation-Metric-Space A B f) =
- ( map-short-function-cauchy-approximation-Metric-Space A C
- (comp-short-function-Metric-Space A B C g f))
- eq-comp-map-short-function-cauchy-approximation-Metric-Space = refl
-```
-
### Homotopic Cauchy approximations are equal
```agda
diff --git a/src/metric-spaces/cauchy-approximations-pseudometric-spaces.lagda.md b/src/metric-spaces/cauchy-approximations-pseudometric-spaces.lagda.md
index 3f7b863d42..280b955661 100644
--- a/src/metric-spaces/cauchy-approximations-pseudometric-spaces.lagda.md
+++ b/src/metric-spaces/cauchy-approximations-pseudometric-spaces.lagda.md
@@ -19,6 +19,7 @@ open import foundation.propositions
open import foundation.subtypes
open import foundation.universe-levels
+open import metric-spaces.isometries-pseudometric-spaces
open import metric-spaces.pseudometric-spaces
open import metric-spaces.short-functions-pseudometric-spaces
```
@@ -103,31 +104,6 @@ module _
refl-neighborhood-Pseudometric-Space A (ε +ℚ⁺ δ) x
```
-### The action of short maps on Cauchy approximations
-
-```agda
-module _
- {l1 l2 l1' l2' : Level}
- (A : Pseudometric-Space l1 l2) (B : Pseudometric-Space l1' l2')
- (f : short-function-Pseudometric-Space A B)
- where
-
- map-short-function-cauchy-approximation-Pseudometric-Space :
- cauchy-approximation-Pseudometric-Space A →
- cauchy-approximation-Pseudometric-Space B
- map-short-function-cauchy-approximation-Pseudometric-Space (u , H) =
- ( map-short-function-Pseudometric-Space A B f ∘ u ,
- λ ε δ →
- is-short-map-short-function-Pseudometric-Space
- ( A)
- ( B)
- ( f)
- ( ε +ℚ⁺ δ)
- ( u ε)
- ( u δ)
- ( H ε δ))
-```
-
### Homotopic Cauchy approximations are equal
```agda
diff --git a/src/metric-spaces/cauchy-pseudocompletion-of-complete-metric-spaces.lagda.md b/src/metric-spaces/cauchy-pseudocompletion-of-complete-metric-spaces.lagda.md
new file mode 100644
index 0000000000..2e96dafb96
--- /dev/null
+++ b/src/metric-spaces/cauchy-pseudocompletion-of-complete-metric-spaces.lagda.md
@@ -0,0 +1,280 @@
+# Cauchy pseudocompletions of complete metric space
+
+```agda
+module metric-spaces.cauchy-pseudocompletion-of-complete-metric-spaces where
+```
+
+Imports
+
+```agda
+open import elementary-number-theory.addition-positive-rational-numbers
+open import elementary-number-theory.positive-rational-numbers
+
+open import foundation.action-on-identifications-functions
+open import foundation.binary-relations
+open import foundation.dependent-pair-types
+open import foundation.function-types
+open import foundation.homotopies
+open import foundation.identity-types
+open import foundation.transport-along-identifications
+open import foundation.universe-levels
+
+open import metric-spaces.cauchy-approximations-in-cauchy-pseudocompletions-of-pseudometric-spaces
+open import metric-spaces.cauchy-approximations-metric-spaces
+open import metric-spaces.cauchy-approximations-pseudometric-spaces
+open import metric-spaces.cauchy-pseudocompletion-of-metric-spaces
+open import metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces
+open import metric-spaces.complete-metric-spaces
+open import metric-spaces.functions-pseudometric-spaces
+open import metric-spaces.isometries-pseudometric-spaces
+open import metric-spaces.limits-of-cauchy-approximations-metric-spaces
+open import metric-spaces.limits-of-cauchy-approximations-pseudometric-spaces
+open import metric-spaces.metric-spaces
+open import metric-spaces.pseudometric-spaces
+open import metric-spaces.rational-neighborhood-relations
+open import metric-spaces.short-functions-pseudometric-spaces
+open import metric-spaces.similarity-of-elements-pseudometric-spaces
+```
+
+
+
+## Idea
+
+Any [complete](metric-spaces.complete-metric-spaces.md) is a
+[retract](foundation.retracts-of-types.md) of its
+[cauchy pseudocompletion](metric-spaces.cauchy-pseudocompletion-of-metric-spaces.md).
+
+## Properties
+
+### Any complete metric space is a short retract of its Cauchy pseudocompletion
+
+```agda
+module _
+ {l1 l2 : Level} (M : Metric-Space l1 l2)
+ (is-complete-M : is-complete-Metric-Space M)
+ where
+
+ map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ type-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( pseudometric-Metric-Space M)
+ map-lim-cauchy-pseudocompletion-is-complete-Metric-Space =
+ limit-cauchy-approximation-Complete-Metric-Space
+ ( M , is-complete-M)
+
+ is-limit-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ (u : cauchy-approximation-Metric-Space M) →
+ is-limit-cauchy-approximation-Metric-Space
+ ( M)
+ ( u)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
+ is-limit-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space =
+ is-limit-limit-cauchy-approximation-Complete-Metric-Space
+ ( M , is-complete-M)
+
+ sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ (u : cauchy-approximation-Metric-Space M) →
+ sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( u)
+ ( const-cauchy-approximation-Metric-Space
+ ( M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u))
+ sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u =
+ sim-const-is-limit-cauchy-approximation-Metric-Space
+ ( M)
+ ( u)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
+ ( is-limit-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
+
+ is-short-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ is-short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( ( const-cauchy-approximation-Metric-Space M) ∘
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space))
+ is-short-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ d x y =
+ preserves-neighborhoods-sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ { x}
+ { const-cauchy-approximation-Metric-Space
+ ( M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space x)}
+ { y}
+ { const-cauchy-approximation-Metric-Space
+ ( M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space y)}
+ ( sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( x))
+ ( sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( y))
+ ( d)
+
+ is-short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ is-short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( pseudometric-Metric-Space M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space)
+ is-short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space d x y Nxy =
+ saturated-neighborhood-Metric-Space
+ ( M)
+ ( d)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space x)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space y)
+ ( lemma-saturated-neighborhood-map-lim)
+ where
+
+ lemma-saturated-neighborhood-map-lim :
+ (δ : ℚ⁺) →
+ neighborhood-Metric-Space
+ ( M)
+ ( d +ℚ⁺ δ)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space x)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space y)
+ lemma-saturated-neighborhood-map-lim δ =
+ tr
+ ( is-upper-bound-dist-Metric-Space
+ ( M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space x)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space y))
+ ( ap (add-ℚ⁺' d) (eq-add-split-ℚ⁺ δ) ∙ commutative-add-ℚ⁺ δ d)
+ ( is-short-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( d)
+ ( x)
+ ( y)
+ ( Nxy)
+ ( left-summand-split-ℚ⁺ δ)
+ ( right-summand-split-ℚ⁺ δ))
+
+ short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ short-function-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( pseudometric-Metric-Space M)
+ short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space =
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space ,
+ is-short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space)
+
+ is-retraction-map-cauchy-pseudocompletion-is-complete-Metric-Space :
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space ∘
+ map-cauchy-pseudocompletion-Metric-Space M) ~
+ ( id)
+ is-retraction-map-cauchy-pseudocompletion-is-complete-Metric-Space =
+ is-retraction-limit-cauchy-approximation-Complete-Metric-Space
+ ( M , is-complete-M)
+
+ sim-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ (u : cauchy-approximation-Metric-Space M) →
+ sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( u)
+ ( map-cauchy-pseudocompletion-Metric-Space
+ ( M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u))
+ sim-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u =
+ sim-const-is-limit-cauchy-approximation-Metric-Space
+ ( M)
+ ( u)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
+ ( is-limit-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
+```
+
+### The isometry mapping a Cauchy approximation in a complete metric space to its limit
+
+```agda
+module _
+ {l1 l2 : Level} (M : Metric-Space l1 l2)
+ (is-complete-M : is-complete-Metric-Space M)
+ where
+
+ abstract
+ reflects-neighborhoods-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ (δ : ℚ⁺) →
+ (u v : cauchy-approximation-Metric-Space M) →
+ neighborhood-Metric-Space
+ ( M)
+ ( δ)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( u))
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( v)) →
+ neighborhood-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( δ)
+ ( u)
+ ( v)
+ reflects-neighborhoods-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ δ x y Nδ =
+ reflects-neighborhoods-sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ { x}
+ { const-cauchy-approximation-Metric-Space
+ ( M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( x))}
+ { y}
+ { const-cauchy-approximation-Metric-Space
+ ( M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( y))}
+ ( sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( x))
+ ( sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( y))
+ ( δ)
+ ( preserves-neighborhoods-map-isometry-Pseudometric-Space
+ ( pseudometric-Metric-Space M)
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( isometry-cauchy-pseudocompletion-Metric-Space M)
+ ( δ)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( x))
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( y))
+ ( Nδ))
+
+ is-isometry-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ is-isometry-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( pseudometric-Metric-Space M)
+ ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M))
+ is-isometry-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space d x y =
+ ( ( is-short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)
+ ( d)
+ ( x)
+ ( y)) ,
+ ( reflects-neighborhoods-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( d)
+ ( x)
+ ( y)))
+
+ isometry-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
+ isometry-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( pseudometric-Metric-Space M)
+ isometry-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space =
+ ( ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
+ ( M)
+ ( is-complete-M)) ,
+ ( is-isometry-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space))
+```
diff --git a/src/metric-spaces/cauchy-pseudocompletion-of-metric-spaces.lagda.md b/src/metric-spaces/cauchy-pseudocompletion-of-metric-spaces.lagda.md
index 9dad3ad654..172816aae7 100644
--- a/src/metric-spaces/cauchy-pseudocompletion-of-metric-spaces.lagda.md
+++ b/src/metric-spaces/cauchy-pseudocompletion-of-metric-spaces.lagda.md
@@ -9,28 +9,22 @@ module metric-spaces.cauchy-pseudocompletion-of-metric-spaces where
```agda
open import elementary-number-theory.addition-positive-rational-numbers
open import elementary-number-theory.positive-rational-numbers
-open import elementary-number-theory.strict-inequality-rational-numbers
-open import foundation.action-on-identifications-binary-functions
open import foundation.action-on-identifications-functions
open import foundation.binary-relations
-open import foundation.binary-transport
open import foundation.dependent-pair-types
open import foundation.function-types
open import foundation.homotopies
open import foundation.identity-types
-open import foundation.propositions
open import foundation.transport-along-identifications
open import foundation.universe-levels
+open import metric-spaces.cauchy-approximations-in-cauchy-pseudocompletions-of-pseudometric-spaces
open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.cauchy-approximations-pseudometric-spaces
open import metric-spaces.cauchy-pseudocompletion-of-pseudometric-spaces
-open import metric-spaces.complete-metric-spaces
-open import metric-spaces.convergent-cauchy-approximations-metric-spaces
open import metric-spaces.functions-pseudometric-spaces
open import metric-spaces.isometries-pseudometric-spaces
-open import metric-spaces.limits-of-cauchy-approximations-metric-spaces
open import metric-spaces.limits-of-cauchy-approximations-pseudometric-spaces
open import metric-spaces.metric-spaces
open import metric-spaces.pseudometric-spaces
@@ -213,47 +207,6 @@ module _
( isometry-cauchy-pseudocompletion-Metric-Space)
```
-### Convergent Cauchy approximations are similar to constant Cauchy approximations in the Cauchy pseudocompletion
-
-```agda
-module _
- {l1 l2 : Level} (M : Metric-Space l1 l2)
- (u : cauchy-approximation-Metric-Space M)
- (x : type-Metric-Space M)
- where
-
- abstract
- sim-const-is-limit-cauchy-approximation-Metric-Space :
- is-limit-cauchy-approximation-Metric-Space M u x →
- sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- ( u)
- ( const-cauchy-approximation-Metric-Space M x)
- sim-const-is-limit-cauchy-approximation-Metric-Space H d α β =
- monotonic-neighborhood-Metric-Space
- ( M)
- ( map-cauchy-approximation-Metric-Space M u α)
- ( x)
- ( α +ℚ⁺ β)
- ( α +ℚ⁺ β +ℚ⁺ d)
- ( le-left-add-ℚ⁺ (α +ℚ⁺ β) d)
- ( H α β)
-
- is-limit-sim-const-cauchy-approximation-Metric-Space :
- sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- ( u)
- ( const-cauchy-approximation-Metric-Space M x) →
- is-limit-cauchy-approximation-Metric-Space M u x
- is-limit-sim-const-cauchy-approximation-Metric-Space H α β =
- saturated-neighborhood-Metric-Space
- ( M)
- ( α +ℚ⁺ β)
- ( map-cauchy-approximation-Metric-Space M u α)
- ( x)
- ( λ d → H d α β)
-```
-
### Any Cauchy approximation in the Cauchy pseudocompletion of a metric space has a limit
```agda
@@ -304,136 +257,3 @@ module _
isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
( pseudometric-Metric-Space M)
```
-
-### Any complete metric space is a short retract of its Cauchy pseudocompletion
-
-```agda
-module _
- {l1 l2 : Level} (M : Metric-Space l1 l2)
- (is-complete-M : is-complete-Metric-Space M)
- where
-
- map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
- type-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- ( pseudometric-Metric-Space M)
- map-lim-cauchy-pseudocompletion-is-complete-Metric-Space =
- limit-cauchy-approximation-Complete-Metric-Space
- ( M , is-complete-M)
-
- is-limit-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
- (u : cauchy-approximation-Metric-Space M) →
- is-limit-cauchy-approximation-Metric-Space
- ( M)
- ( u)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
- is-limit-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space =
- is-limit-limit-cauchy-approximation-Complete-Metric-Space
- ( M , is-complete-M)
-
- sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
- (u : cauchy-approximation-Metric-Space M) →
- sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- ( u)
- ( const-cauchy-approximation-Metric-Space
- ( M)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u))
- sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u =
- sim-const-is-limit-cauchy-approximation-Metric-Space
- ( M)
- ( u)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
- ( is-limit-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
-
- is-short-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
- is-short-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- ( cauchy-pseudocompletion-Metric-Space M)
- ( ( const-cauchy-approximation-Metric-Space M) ∘
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space))
- is-short-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
- d x y =
- preserves-neighborhood-sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- { x}
- { const-cauchy-approximation-Metric-Space
- ( M)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space x)}
- { y}
- { const-cauchy-approximation-Metric-Space
- ( M)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space y)}
- ( sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
- ( x))
- ( sim-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
- ( y))
- ( d)
-
- is-short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
- is-short-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- ( pseudometric-Metric-Space M)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space)
- is-short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space d x y Nxy =
- saturated-neighborhood-Metric-Space
- ( M)
- ( d)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space x)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space y)
- ( lemma-saturated-neighborhood-map-lim)
- where
-
- lemma-saturated-neighborhood-map-lim :
- (δ : ℚ⁺) →
- neighborhood-Metric-Space
- ( M)
- ( d +ℚ⁺ δ)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space x)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space y)
- lemma-saturated-neighborhood-map-lim δ =
- tr
- ( is-upper-bound-dist-Metric-Space
- ( M)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space x)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space y))
- ( ap (add-ℚ⁺' d) (eq-add-split-ℚ⁺ δ) ∙ commutative-add-ℚ⁺ δ d)
- ( is-short-const-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space
- ( d)
- ( x)
- ( y)
- ( Nxy)
- ( left-summand-split-ℚ⁺ δ)
- ( right-summand-split-ℚ⁺ δ))
-
- short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
- short-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- ( pseudometric-Metric-Space M)
- short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space =
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space ,
- is-short-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space)
-
- is-retraction-map-cauchy-pseudocompletion-is-complete-Metric-Space :
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space ∘
- map-cauchy-pseudocompletion-Metric-Space M) ~
- ( id)
- is-retraction-map-cauchy-pseudocompletion-is-complete-Metric-Space =
- is-retraction-limit-cauchy-approximation-Complete-Metric-Space
- ( M , is-complete-M)
-
- sim-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space :
- (u : cauchy-approximation-Metric-Space M) →
- sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Metric-Space M)
- ( u)
- ( map-cauchy-pseudocompletion-Metric-Space
- ( M)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u))
- sim-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u =
- sim-const-is-limit-cauchy-approximation-Metric-Space
- ( M)
- ( u)
- ( map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
- ( is-limit-map-lim-cauchy-pseudocompletion-is-complete-Metric-Space u)
-```
diff --git a/src/metric-spaces/cauchy-pseudocompletion-of-pseudometric-spaces.lagda.md b/src/metric-spaces/cauchy-pseudocompletion-of-pseudometric-spaces.lagda.md
index 5bc301fcc1..044b7d09c6 100644
--- a/src/metric-spaces/cauchy-pseudocompletion-of-pseudometric-spaces.lagda.md
+++ b/src/metric-spaces/cauchy-pseudocompletion-of-pseudometric-spaces.lagda.md
@@ -17,24 +17,16 @@ open import elementary-number-theory.strict-inequality-rational-numbers
open import foundation.action-on-identifications-binary-functions
open import foundation.action-on-identifications-functions
open import foundation.binary-relations
-open import foundation.binary-transport
open import foundation.dependent-pair-types
open import foundation.function-types
-open import foundation.homotopies
open import foundation.identity-types
open import foundation.propositions
open import foundation.transport-along-identifications
open import foundation.universe-levels
-open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.cauchy-approximations-pseudometric-spaces
-open import metric-spaces.complete-metric-spaces
-open import metric-spaces.convergent-cauchy-approximations-metric-spaces
-open import metric-spaces.functions-pseudometric-spaces
open import metric-spaces.isometries-pseudometric-spaces
-open import metric-spaces.limits-of-cauchy-approximations-metric-spaces
open import metric-spaces.limits-of-cauchy-approximations-pseudometric-spaces
-open import metric-spaces.metric-spaces
open import metric-spaces.pseudometric-spaces
open import metric-spaces.rational-neighborhood-relations
open import metric-spaces.short-functions-pseudometric-spaces
@@ -303,7 +295,7 @@ module _
const-cauchy-approximation-Pseudometric-Space M
abstract
- preserves-neighborhood-map-cauchy-pseudocompletion-Pseudometric-Space :
+ preserves-neighborhoods-map-cauchy-pseudocompletion-Pseudometric-Space :
(d : ℚ⁺) (x y : type-Pseudometric-Space M) →
neighborhood-Pseudometric-Space M d x y →
neighborhood-cauchy-pseudocompletion-Pseudometric-Space
@@ -311,13 +303,13 @@ module _
( d)
( map-cauchy-pseudocompletion-Pseudometric-Space x)
( map-cauchy-pseudocompletion-Pseudometric-Space y)
- preserves-neighborhood-map-cauchy-pseudocompletion-Pseudometric-Space
+ preserves-neighborhoods-map-cauchy-pseudocompletion-Pseudometric-Space
d x y Nxy δ ε =
monotonic-neighborhood-Pseudometric-Space M x y d (δ +ℚ⁺ ε +ℚ⁺ d)
( le-right-add-ℚ⁺ (δ +ℚ⁺ ε) d)
( Nxy)
- reflects-neighborhood-map-cauchy-pseudocompletion-Pseudometric-Space :
+ reflects-neighborhoods-map-cauchy-pseudocompletion-Pseudometric-Space :
(d : ℚ⁺) (x y : type-Pseudometric-Space M) →
neighborhood-cauchy-pseudocompletion-Pseudometric-Space
( M)
@@ -325,7 +317,7 @@ module _
( map-cauchy-pseudocompletion-Pseudometric-Space x)
( map-cauchy-pseudocompletion-Pseudometric-Space y) →
neighborhood-Pseudometric-Space M d x y
- reflects-neighborhood-map-cauchy-pseudocompletion-Pseudometric-Space
+ reflects-neighborhoods-map-cauchy-pseudocompletion-Pseudometric-Space
d x y Nxy =
saturated-neighborhood-Pseudometric-Space M d x y
( λ δ →
@@ -343,11 +335,11 @@ module _
( cauchy-pseudocompletion-Pseudometric-Space M)
( map-cauchy-pseudocompletion-Pseudometric-Space)
is-isometry-map-cauchy-pseudocompletion-Pseudometric-Space d x y =
- ( ( preserves-neighborhood-map-cauchy-pseudocompletion-Pseudometric-Space
+ ( ( preserves-neighborhoods-map-cauchy-pseudocompletion-Pseudometric-Space
( d)
( x)
( y)) ,
- (reflects-neighborhood-map-cauchy-pseudocompletion-Pseudometric-Space
+ (reflects-neighborhoods-map-cauchy-pseudocompletion-Pseudometric-Space
( d)
( x)
( y)))
@@ -412,449 +404,60 @@ module _
( λ d → H d α β)
```
-### Any Cauchy approximation in the Cauchy pseudocompletion of a pseudometric space has a limit
+### Similarity in the Cauchy pseudocompletion preserves and reflects limits
```agda
module _
- { l1 l2 : Level} (M : Pseudometric-Space l1 l2)
- ( U :
- cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- where
-
- map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- ℚ⁺ → ℚ⁺ → type-Pseudometric-Space M
- map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space ε =
- map-cauchy-approximation-Pseudometric-Space M
- ( map-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( U)
- ( ε))
-
- is-cauchy-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- (δ ε d₁ d₂ : ℚ⁺) →
- neighborhood-Pseudometric-Space
- ( M)
- ( d₁ +ℚ⁺ d₂ +ℚ⁺ (δ +ℚ⁺ ε))
- ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( δ)
- ( d₁))
- ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( ε)
- ( d₂))
- is-cauchy-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- =
- is-cauchy-approximation-map-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( U)
-
- map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- ℚ⁺ → type-Pseudometric-Space M
- map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space d =
- let
- (d₁ , d₂ , _) = split-ℚ⁺ d
- in
- map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space d₂ d₁
-
- is-cauchy-map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- is-cauchy-approximation-Pseudometric-Space
- ( M)
- ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
- is-cauchy-map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- δ ε =
- let
- (δ₁ , δ₂ , δ₁+δ₂=δ) = split-ℚ⁺ δ
- (ε₁ , ε₂ , ε₁+ε₂=ε) = split-ℚ⁺ ε
-
- lemma-δ+ε :
- ((δ₁ +ℚ⁺ ε₁) +ℚ⁺ (δ₂ +ℚ⁺ ε₂)) = δ +ℚ⁺ ε
- lemma-δ+ε =
- ( interchange-law-add-add-ℚ⁺ δ₁ ε₁ δ₂ ε₂) ∙
- ( ap-binary add-ℚ⁺ δ₁+δ₂=δ ε₁+ε₂=ε)
- in
- tr
- ( is-upper-bound-dist-Pseudometric-Space
- ( M)
- ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( δ))
- ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( ε)))
- ( lemma-δ+ε)
- ( is-cauchy-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- _ _ _ _)
-
- lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- cauchy-approximation-Pseudometric-Space M
- lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space =
- ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space ,
- is-cauchy-map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
-
- is-limit-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- is-limit-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( U)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
- is-limit-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- δ ε η θ =
- let
- (θ₁ , θ₂ , θ₁+θ₂=θ) = split-ℚ⁺ θ
-
- lemma-η+θ+δ :
- ((η +ℚ⁺ θ₁) +ℚ⁺ (δ +ℚ⁺ θ₂)) = η +ℚ⁺ θ +ℚ⁺ δ
- lemma-η+θ+δ =
- ( interchange-law-add-add-ℚ⁺ η θ₁ δ θ₂) ∙
- ( ap
- ( add-ℚ⁺ (η +ℚ⁺ δ))
- ( θ₁+θ₂=θ)) ∙
- ( associative-add-ℚ⁺ η δ θ) ∙
- ( ap
- ( add-ℚ⁺ η)
- ( commutative-add-ℚ⁺ δ θ)) ∙
- ( inv (associative-add-ℚ⁺ η θ δ))
-
- lemma-lim :
- neighborhood-Pseudometric-Space M
- ( η +ℚ⁺ θ +ℚ⁺ δ)
- ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( δ)
- ( η))
- ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( θ₂)
- ( θ₁))
- lemma-lim =
- tr
- ( is-upper-bound-dist-Pseudometric-Space M
- ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( δ)
- ( η))
- ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( θ)))
- ( lemma-η+θ+δ)
- ( is-cauchy-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- _ _ _ _)
- in
- tr
- ( is-upper-bound-dist-Pseudometric-Space M
- ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( δ)
- ( η))
- ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( θ)))
- ( associative-add-ℚ⁺
- ( η +ℚ⁺ θ)
- ( δ)
- ( ε))
- ( monotonic-neighborhood-Pseudometric-Space M
- ( map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( δ)
- ( η))
- ( map-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( θ))
- ( η +ℚ⁺ θ +ℚ⁺ δ)
- ( η +ℚ⁺ θ +ℚ⁺ δ +ℚ⁺ ε)
- ( le-left-add-ℚ⁺ ( η +ℚ⁺ θ +ℚ⁺ δ) ε)
- ( lemma-lim))
-
- has-limit-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- Σ ( cauchy-approximation-Pseudometric-Space M)
- ( is-limit-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( U))
- has-limit-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space =
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space ,
- is-limit-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
-```
-
-### Any Cauchy approximation in the pseudometric completion is similar to the constant Cauchy approximation of its limit
-
-```agda
-module _
- { l1 l2 : Level} (M : Pseudometric-Space l1 l2)
- ( u :
- cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
+ {l1 l2 : Level} (M : Pseudometric-Space l1 l2)
+ (u v : cauchy-approximation-Pseudometric-Space M)
+ (x : type-Pseudometric-Space M)
where
- sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
+ has-same-limit-sim-cauchy-approximation-Pseudometric-Space :
sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( u)
- ( const-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u)))
- sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- =
- sim-const-is-limit-cauchy-approximation-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space M)
( u)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M u)
- ( is-limit-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u))
-```
-
-### The map from a Cauchy approximation in the pseudometric completion to its limit is short
-
-```agda
-module _
- {l1 l2 : Level} (M : Pseudometric-Space l1 l2)
- where
-
- abstract
- is-short-function-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- is-short-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( ( const-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)) ∘
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)))
- is-short-function-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- d u v =
- preserves-neighborhood-sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- { u}
- { const-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u))}
- { v}
- { const-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( v))}
- ( sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u))
- ( sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( v))
- ( d)
-
- is-short-function-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space :
- is-short-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M)
- is-short-function-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space
- d u v Nuv =
- reflects-neighborhood-map-cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( d)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u))
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( v))
- ( is-short-function-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( d)
- ( u)
- ( v)
- ( Nuv))
-
- short-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space :
- short-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- short-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space =
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M ,
- is-short-function-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space)
-```
-
-### The map from a Cauchy approximation in the pseudometric completion to its limit is an isometry
-
-```agda
-module _
- {l1 l2 : Level} (M : Pseudometric-Space l1 l2)
- where
-
- abstract
- reflects-neighborhood-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- ( d : ℚ⁺) →
- ( u v :
- cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)) →
- neighborhood-Pseudometric-Space
+ ( v) →
+ is-limit-cauchy-approximation-Pseudometric-Space M u x →
+ is-limit-cauchy-approximation-Pseudometric-Space M v x
+ has-same-limit-sim-cauchy-approximation-Pseudometric-Space u~v lim-u =
+ is-limit-sim-const-cauchy-approximation-Pseudometric-Space
+ ( M)
+ ( v)
+ ( x)
+ ( transitive-sim-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space M)
- ( d)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u))
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( v)) →
- neighborhood-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( d)
- ( u)
( v)
- reflects-neighborhood-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- d u v N-lim =
- reflects-neighborhood-sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- { u}
- { const-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u))}
- { v}
- { const-cauchy-approximation-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( v))}
- ( sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u))
- ( sim-const-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( v))
- ( d)
- ( preserves-neighborhood-map-cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( d)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( u))
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( M)
- ( v))
- ( N-lim))
-
- is-isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- is-isometry-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M)
- is-isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- d x y =
- ( ( is-short-function-lim-cauchy-approximation-pseudocompletion-Pseudometric-Space
+ ( u)
+ ( const-cauchy-approximation-Pseudometric-Space M x)
+ ( sim-const-is-limit-cauchy-approximation-Pseudometric-Space
( M)
- ( d)
- ( x)
- ( y)) ,
- ( reflects-neighborhood-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space
- ( d)
+ ( u)
( x)
- ( y)))
-
- isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- isometry-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space =
- ( lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space M ,
- is-isometry-lim-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space)
-```
-
-### The action of short maps on Cauchy approximations is short
-
-```agda
-module _
- {l1 l2 l1' l2' : Level}
- (A : Pseudometric-Space l1 l2) (B : Pseudometric-Space l1' l2')
- (f : short-function-Pseudometric-Space A B)
- where
-
- is-short-map-short-function-cauchy-approximation-Pseudometric-Space :
- is-short-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space A)
- ( cauchy-pseudocompletion-Pseudometric-Space B)
- ( map-short-function-cauchy-approximation-Pseudometric-Space A B f)
- is-short-map-short-function-cauchy-approximation-Pseudometric-Space
- d x y Nxy α β =
- is-short-map-short-function-Pseudometric-Space A B f
- ( α +ℚ⁺ β +ℚ⁺ d)
- ( map-cauchy-approximation-Pseudometric-Space A x α)
- ( map-cauchy-approximation-Pseudometric-Space A y β)
- ( Nxy α β)
-
- short-map-short-function-cauchy-approximation-Pseudometric-Space :
- short-function-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space A)
- ( cauchy-pseudocompletion-Pseudometric-Space B)
- short-map-short-function-cauchy-approximation-Pseudometric-Space =
- ( map-short-function-cauchy-approximation-Pseudometric-Space A B f ,
- is-short-map-short-function-cauchy-approximation-Pseudometric-Space)
-```
-
-### The image of a Cauchy approximation in the Cauchy pseudocompletion is convergent
-
-```agda
-module _
- {l1 l2 : Level} (M : Pseudometric-Space l1 l2)
- (u : cauchy-approximation-Pseudometric-Space M)
- where
+ ( lim-u))
+ ( inv-sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( u~v)))
- is-limit-map-cauchy-approximation-cauchy-pseudocompletion-Ppseudometric-Space :
- is-limit-cauchy-approximation-Pseudometric-Space
+ sim-has-same-limit-cauchy-approximation-Pseudometric-Space :
+ is-limit-cauchy-approximation-Pseudometric-Space M u x →
+ is-limit-cauchy-approximation-Pseudometric-Space M v x →
+ sim-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space M)
- ( map-short-function-cauchy-approximation-Pseudometric-Space
- ( M)
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( short-map-cauchy-pseudocompletion-Pseudometric-Space M)
- ( u))
( u)
- is-limit-map-cauchy-approximation-cauchy-pseudocompletion-Ppseudometric-Space
- ε δ α β =
- symmetric-neighborhood-Pseudometric-Space M
- ( (α +ℚ⁺ β) +ℚ⁺ (ε +ℚ⁺ δ))
- ( map-cauchy-approximation-Pseudometric-Space M u β)
- ( map-cauchy-approximation-Pseudometric-Space M u ε)
- ( monotonic-neighborhood-Pseudometric-Space M
- ( map-cauchy-approximation-Pseudometric-Space M u β)
- ( map-cauchy-approximation-Pseudometric-Space M u ε)
- ( β +ℚ⁺ ε)
- ( (α +ℚ⁺ β) +ℚ⁺ (ε +ℚ⁺ δ))
- ( preserves-le-add-ℚ
- { rational-ℚ⁺ β}
- { rational-ℚ⁺ (α +ℚ⁺ β)}
- { rational-ℚ⁺ ε}
- { rational-ℚ⁺ (ε +ℚ⁺ δ)}
- ( le-right-add-ℚ⁺ α β)
- ( le-left-add-ℚ⁺ ε δ))
- ( is-cauchy-approximation-map-cauchy-approximation-Pseudometric-Space
- ( M)
- ( u)
- ( β)
- ( ε)))
-
- sim-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space :
- sim-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M))
- ( map-short-function-cauchy-approximation-Pseudometric-Space
- ( M)
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( short-map-cauchy-pseudocompletion-Pseudometric-Space M)
- ( u))
- ( map-cauchy-pseudocompletion-Pseudometric-Space
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( u))
- sim-map-cauchy-approximation-cauchy-pseudocompletion-Pseudometric-Space =
- sim-const-is-limit-cauchy-approximation-Pseudometric-Space
+ ( v)
+ sim-has-same-limit-cauchy-approximation-Pseudometric-Space lim-u lim-v =
+ transitive-sim-Pseudometric-Space
( cauchy-pseudocompletion-Pseudometric-Space M)
- ( map-short-function-cauchy-approximation-Pseudometric-Space
- ( M)
- ( cauchy-pseudocompletion-Pseudometric-Space M)
- ( short-map-cauchy-pseudocompletion-Pseudometric-Space M)
- ( u))
( u)
- ( is-limit-map-cauchy-approximation-cauchy-pseudocompletion-Ppseudometric-Space)
+ ( const-cauchy-approximation-Pseudometric-Space M x)
+ ( v)
+ ( inv-sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Pseudometric-Space M)
+ ( sim-const-is-limit-cauchy-approximation-Pseudometric-Space
+ ( M)
+ ( v)
+ ( x)
+ ( lim-v)))
+ ( sim-const-is-limit-cauchy-approximation-Pseudometric-Space M u x lim-u)
```
diff --git a/src/metric-spaces/dependent-products-metric-spaces.lagda.md b/src/metric-spaces/dependent-products-metric-spaces.lagda.md
index 2675d11b69..cba39fb490 100644
--- a/src/metric-spaces/dependent-products-metric-spaces.lagda.md
+++ b/src/metric-spaces/dependent-products-metric-spaces.lagda.md
@@ -15,6 +15,7 @@ open import foundation.propositions
open import foundation.sets
open import foundation.universe-levels
+open import metric-spaces.action-on-cauchy-approximations-short-maps-metric-spaces
open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.complete-metric-spaces
open import metric-spaces.convergent-cauchy-approximations-metric-spaces
@@ -171,7 +172,7 @@ module _
ev-cauchy-approximation-Π-Metric-Space :
(x : A) → cauchy-approximation-Metric-Space (P x)
ev-cauchy-approximation-Π-Metric-Space x =
- map-short-function-cauchy-approximation-Metric-Space
+ map-cauchy-approximation-short-function-Metric-Space
( Π-Metric-Space A P)
( P x)
( short-ev-Π-Metric-Space A P x)
diff --git a/src/metric-spaces/indexed-sums-metric-spaces.lagda.md b/src/metric-spaces/indexed-sums-metric-spaces.lagda.md
index 4ed15b71da..c07e513fe3 100644
--- a/src/metric-spaces/indexed-sums-metric-spaces.lagda.md
+++ b/src/metric-spaces/indexed-sums-metric-spaces.lagda.md
@@ -295,7 +295,7 @@ module _
( map-emb-fiber-indexed-sum-Metric-Space A P x ,
is-short-emb-fiber-indexed-sum-Metric-Space)
- reflects-neighborhood-emb-fiber-indexed-sum-Metric-Space :
+ reflects-neighborhoods-emb-fiber-indexed-sum-Metric-Space :
(d : ℚ⁺) (px px' : type-Metric-Space (P x)) →
neighborhood-Metric-Space
( indexed-sum-Metric-Space A P)
@@ -307,7 +307,8 @@ module _
( d)
( px)
( px')
- reflects-neighborhood-emb-fiber-indexed-sum-Metric-Space d px px' (e , Nxx') =
+ reflects-neighborhoods-emb-fiber-indexed-sum-Metric-Space
+ d px px' (e , Nxx') =
inv-tr
( λ e' →
neighborhood-Metric-Space
@@ -328,7 +329,7 @@ module _
( map-emb-fiber-indexed-sum-Metric-Space A P x)
is-isometry-emb-fiber-indexed-sum-Metric-Space d px px' =
( is-short-emb-fiber-indexed-sum-Metric-Space d px px' ,
- reflects-neighborhood-emb-fiber-indexed-sum-Metric-Space d px px')
+ reflects-neighborhoods-emb-fiber-indexed-sum-Metric-Space d px px')
isometry-emb-fiber-indexed-Metric-Space :
isometry-Metric-Space (P x) (indexed-sum-Metric-Space A P)
diff --git a/src/metric-spaces/isometries-metric-spaces.lagda.md b/src/metric-spaces/isometries-metric-spaces.lagda.md
index 3fee4dcad8..92c1c0a3e8 100644
--- a/src/metric-spaces/isometries-metric-spaces.lagda.md
+++ b/src/metric-spaces/isometries-metric-spaces.lagda.md
@@ -125,8 +125,8 @@ module _
is-isometry-Metric-Space A A (id-Metric-Space A)
is-isometry-id-Metric-Space d x y = id-iff
- isometry-id-Metric-Space : isometry-Metric-Space A A
- isometry-id-Metric-Space =
+ id-isometry-Metric-Space : isometry-Metric-Space A A
+ id-isometry-Metric-Space =
id-Metric-Space A , is-isometry-id-Metric-Space
```
@@ -171,7 +171,7 @@ module _
(f : isometry-Metric-Space A B)
where
- preserves-neighborhood-map-isometry-Metric-Space :
+ preserves-neighborhoods-map-isometry-Metric-Space :
(d : ℚ⁺) (x y : type-Metric-Space A) →
neighborhood-Metric-Space A d x y →
neighborhood-Metric-Space
@@ -179,11 +179,11 @@ module _
( d)
( map-isometry-Metric-Space A B f x)
( map-isometry-Metric-Space A B f y)
- preserves-neighborhood-map-isometry-Metric-Space d x y =
+ preserves-neighborhoods-map-isometry-Metric-Space d x y =
forward-implication
( is-isometry-map-isometry-Metric-Space A B f d x y)
- reflects-neighborhood-map-isometry-Metric-Space :
+ reflects-neighborhoods-map-isometry-Metric-Space :
(d : ℚ⁺) (x y : type-Metric-Space A) →
neighborhood-Metric-Space
( B)
@@ -191,7 +191,7 @@ module _
( map-isometry-Metric-Space A B f x)
( map-isometry-Metric-Space A B f y) →
neighborhood-Metric-Space A d x y
- reflects-neighborhood-map-isometry-Metric-Space d x y =
+ reflects-neighborhoods-map-isometry-Metric-Space d x y =
backward-implication
( is-isometry-map-isometry-Metric-Space A B f d x y)
```
@@ -238,7 +238,7 @@ module _
left-unit-law-comp-isometry-Metric-Space :
( comp-isometry-Metric-Space A B B
- (isometry-id-Metric-Space B)
+ ( id-isometry-Metric-Space B)
( f)) =
( f)
left-unit-law-comp-isometry-Metric-Space =
@@ -250,7 +250,7 @@ module _
right-unit-law-comp-isometry-Metric-Space :
( comp-isometry-Metric-Space A A B
( f)
- ( isometry-id-Metric-Space A)) =
+ ( id-isometry-Metric-Space A)) =
( f)
right-unit-law-comp-isometry-Metric-Space =
right-unit-law-comp-isometry-Pseudometric-Space
@@ -335,7 +335,7 @@ module _
B
f
isometry-inv-is-equiv-isometry-Metric-Space) =
- ( isometry-id-Metric-Space B)
+ ( id-isometry-Metric-Space B)
is-section-isometry-inv-is-equiv-isometry-Metric-Space =
is-section-isometry-inv-is-equiv-isometry-Pseudometric-Space
( pseudometric-Metric-Space A)
@@ -350,7 +350,7 @@ module _
A
isometry-inv-is-equiv-isometry-Metric-Space
f) =
- ( isometry-id-Metric-Space A)
+ ( id-isometry-Metric-Space A)
is-retraction-isometry-inv-is-equiv-isometry-Metric-Space =
is-retraction-isometry-inv-is-equiv-isometry-Pseudometric-Space
( pseudometric-Metric-Space A)
diff --git a/src/metric-spaces/isometries-pseudometric-spaces.lagda.md b/src/metric-spaces/isometries-pseudometric-spaces.lagda.md
index 35d81a521c..7147daf5c0 100644
--- a/src/metric-spaces/isometries-pseudometric-spaces.lagda.md
+++ b/src/metric-spaces/isometries-pseudometric-spaces.lagda.md
@@ -113,8 +113,8 @@ module _
is-isometry-Pseudometric-Space A A (id-Pseudometric-Space A)
is-isometry-id-Pseudometric-Space d x y = id-iff
- isometry-id-Pseudometric-Space : isometry-Pseudometric-Space A A
- isometry-id-Pseudometric-Space =
+ id-isometry-Pseudometric-Space : isometry-Pseudometric-Space A A
+ id-isometry-Pseudometric-Space =
( id-Pseudometric-Space A , is-isometry-id-Pseudometric-Space)
```
@@ -162,7 +162,7 @@ module _
(f : isometry-Pseudometric-Space A B)
where
- preserves-neighborhood-map-isometry-Pseudometric-Space :
+ preserves-neighborhoods-map-isometry-Pseudometric-Space :
(d : ℚ⁺) (x y : type-Pseudometric-Space A) →
neighborhood-Pseudometric-Space A d x y →
neighborhood-Pseudometric-Space
@@ -170,11 +170,11 @@ module _
( d)
( map-isometry-Pseudometric-Space A B f x)
( map-isometry-Pseudometric-Space A B f y)
- preserves-neighborhood-map-isometry-Pseudometric-Space d x y =
+ preserves-neighborhoods-map-isometry-Pseudometric-Space d x y =
forward-implication
( is-isometry-map-isometry-Pseudometric-Space A B f d x y)
- reflects-neighborhood-map-isometry-Pseudometric-Space :
+ reflects-neighborhoods-map-isometry-Pseudometric-Space :
(d : ℚ⁺) (x y : type-Pseudometric-Space A) →
neighborhood-Pseudometric-Space
( B)
@@ -182,7 +182,7 @@ module _
( map-isometry-Pseudometric-Space A B f x)
( map-isometry-Pseudometric-Space A B f y) →
neighborhood-Pseudometric-Space A d x y
- reflects-neighborhood-map-isometry-Pseudometric-Space d x y =
+ reflects-neighborhoods-map-isometry-Pseudometric-Space d x y =
backward-implication
( is-isometry-map-isometry-Pseudometric-Space A B f d x y)
```
@@ -232,7 +232,7 @@ module _
left-unit-law-comp-isometry-Pseudometric-Space :
( comp-isometry-Pseudometric-Space A B B
- (isometry-id-Pseudometric-Space B)
+ ( id-isometry-Pseudometric-Space B)
( f)) =
( f)
left-unit-law-comp-isometry-Pseudometric-Space =
@@ -243,7 +243,7 @@ module _
( A)
( B)
( B)
- (isometry-id-Pseudometric-Space B)
+ ( id-isometry-Pseudometric-Space B)
( f))
( f)
( refl-htpy)
@@ -251,7 +251,7 @@ module _
right-unit-law-comp-isometry-Pseudometric-Space :
( comp-isometry-Pseudometric-Space A A B
( f)
- ( isometry-id-Pseudometric-Space A)) =
+ ( id-isometry-Pseudometric-Space A)) =
( f)
right-unit-law-comp-isometry-Pseudometric-Space =
eq-htpy-map-isometry-Pseudometric-Space
@@ -263,7 +263,7 @@ module _
( A)
( B)
( f)
- ( isometry-id-Pseudometric-Space A))
+ ( id-isometry-Pseudometric-Space A))
( refl-htpy)
```
@@ -357,25 +357,25 @@ module _
( comp-isometry-Pseudometric-Space B A B
( f)
( isometry-inv-is-equiv-isometry-Pseudometric-Space)) =
- ( isometry-id-Pseudometric-Space B)
+ ( id-isometry-Pseudometric-Space B)
is-section-isometry-inv-is-equiv-isometry-Pseudometric-Space =
eq-htpy-map-isometry-Pseudometric-Space B B
( comp-isometry-Pseudometric-Space B A B
( f)
( isometry-inv-is-equiv-isometry-Pseudometric-Space))
- ( isometry-id-Pseudometric-Space B)
+ ( id-isometry-Pseudometric-Space B)
( is-section-map-inv-is-equiv E)
is-retraction-isometry-inv-is-equiv-isometry-Pseudometric-Space :
( comp-isometry-Pseudometric-Space A B A
( isometry-inv-is-equiv-isometry-Pseudometric-Space)
( f)) =
- ( isometry-id-Pseudometric-Space A)
+ ( id-isometry-Pseudometric-Space A)
is-retraction-isometry-inv-is-equiv-isometry-Pseudometric-Space =
eq-htpy-map-isometry-Pseudometric-Space A A
( comp-isometry-Pseudometric-Space A B A
( isometry-inv-is-equiv-isometry-Pseudometric-Space)
( f))
- ( isometry-id-Pseudometric-Space A)
+ ( id-isometry-Pseudometric-Space A)
( is-retraction-map-inv-is-equiv E)
```
diff --git a/src/metric-spaces/limits-of-cauchy-approximations-metric-spaces.lagda.md b/src/metric-spaces/limits-of-cauchy-approximations-metric-spaces.lagda.md
index d9a5fe6ea1..38cba6afa2 100644
--- a/src/metric-spaces/limits-of-cauchy-approximations-metric-spaces.lagda.md
+++ b/src/metric-spaces/limits-of-cauchy-approximations-metric-spaces.lagda.md
@@ -10,18 +10,17 @@ module metric-spaces.limits-of-cauchy-approximations-metric-spaces where
open import elementary-number-theory.addition-positive-rational-numbers
open import elementary-number-theory.positive-rational-numbers
-open import foundation.dependent-pair-types
open import foundation.function-types
open import foundation.identity-types
open import foundation.propositions
-open import foundation.subtypes
-open import foundation.transport-along-identifications
open import foundation.universe-levels
open import metric-spaces.cauchy-approximations-metric-spaces
+open import metric-spaces.cauchy-pseudocompletion-of-metric-spaces
open import metric-spaces.limits-of-cauchy-approximations-pseudometric-spaces
open import metric-spaces.metric-spaces
open import metric-spaces.short-functions-metric-spaces
+open import metric-spaces.similarity-of-elements-pseudometric-spaces
```
@@ -144,32 +143,45 @@ module _
( x)
```
-### The action of short maps on Cauchy approximations preserves limits
+### Convergent Cauchy approximations are similar to constant Cauchy approximations in the Cauchy pseudocompletion
```agda
module _
- {l1 l2 l1' l2' : Level}
- (A : Metric-Space l1 l2) (B : Metric-Space l1' l2')
- (f : short-function-Metric-Space A B)
- (a : cauchy-approximation-Metric-Space A)
- (lim : type-Metric-Space A)
+ {l1 l2 : Level} (M : Metric-Space l1 l2)
+ (u : cauchy-approximation-Metric-Space M)
+ (x : type-Metric-Space M)
where
abstract
- preserves-limit-cauchy-approximation-map-short-function-Metric-Space :
- is-limit-cauchy-approximation-Metric-Space A a lim →
- is-limit-cauchy-approximation-Metric-Space
- ( B)
- ( map-short-function-cauchy-approximation-Metric-Space A B f a)
- ( map-short-function-Metric-Space A B f lim)
- preserves-limit-cauchy-approximation-map-short-function-Metric-Space
- is-lim-a ε δ =
- is-short-map-short-function-Metric-Space A B
- ( f)
- ( ε +ℚ⁺ δ)
- ( map-cauchy-approximation-Metric-Space A a ε)
- ( lim)
- ( is-lim-a ε δ)
+ sim-const-is-limit-cauchy-approximation-Metric-Space :
+ is-limit-cauchy-approximation-Metric-Space M u x →
+ sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( u)
+ ( const-cauchy-approximation-Metric-Space M x)
+ sim-const-is-limit-cauchy-approximation-Metric-Space H d α β =
+ monotonic-neighborhood-Metric-Space
+ ( M)
+ ( map-cauchy-approximation-Metric-Space M u α)
+ ( x)
+ ( α +ℚ⁺ β)
+ ( α +ℚ⁺ β +ℚ⁺ d)
+ ( le-left-add-ℚ⁺ (α +ℚ⁺ β) d)
+ ( H α β)
+
+ is-limit-sim-const-cauchy-approximation-Metric-Space :
+ sim-Pseudometric-Space
+ ( cauchy-pseudocompletion-Metric-Space M)
+ ( u)
+ ( const-cauchy-approximation-Metric-Space M x) →
+ is-limit-cauchy-approximation-Metric-Space M u x
+ is-limit-sim-const-cauchy-approximation-Metric-Space H α β =
+ saturated-neighborhood-Metric-Space
+ ( M)
+ ( α +ℚ⁺ β)
+ ( map-cauchy-approximation-Metric-Space M u α)
+ ( x)
+ ( λ d → H d α β)
```
## See also
diff --git a/src/metric-spaces/metric-quotients-of-pseudometric-spaces.lagda.md b/src/metric-spaces/metric-quotients-of-pseudometric-spaces.lagda.md
index ffecd0aafc..d4228503f3 100644
--- a/src/metric-spaces/metric-quotients-of-pseudometric-spaces.lagda.md
+++ b/src/metric-spaces/metric-quotients-of-pseudometric-spaces.lagda.md
@@ -386,6 +386,17 @@ module _
map-subtype-metric-quotient-Pseudometric-Space =
inhabitant-equivalence-class-quotient-map-set-quotient
( equivalence-relation-sim-Pseudometric-Space M)
+
+ eq-map-is-in-class-metric-quotient-Pseudometric-Space :
+ (X : type-metric-quotient-Pseudometric-Space M) →
+ {x : type-Pseudometric-Space M} →
+ is-in-class-metric-quotient-Pseudometric-Space M X x →
+ map-metric-quotient-Pseudometric-Space x = X
+ eq-map-is-in-class-metric-quotient-Pseudometric-Space X {x} x∈X =
+ eq-set-quotient-equivalence-class-set-quotient
+ ( equivalence-relation-sim-Pseudometric-Space M)
+ ( X)
+ ( x∈X)
```
### The mapping from a pseudometric space its quotient metric space is an isometry
@@ -397,7 +408,7 @@ module _
where
abstract
- preserves-neighborhood-map-metric-quotient-Pseudometric-Space :
+ preserves-neighborhoods-map-metric-quotient-Pseudometric-Space :
(d : ℚ⁺) (x y : type-Pseudometric-Space M) →
neighborhood-Pseudometric-Space M d x y →
neighborhood-metric-quotient-Pseudometric-Space
@@ -405,7 +416,7 @@ module _
( d)
( map-metric-quotient-Pseudometric-Space M x)
( map-metric-quotient-Pseudometric-Space M y)
- preserves-neighborhood-map-metric-quotient-Pseudometric-Space
+ preserves-neighborhoods-map-metric-quotient-Pseudometric-Space
d x y d⟨x,y⟩ (x' , x≈x') (y' , y≈y') =
let
x~x' =
@@ -423,15 +434,15 @@ module _
( y≈y')
in
- preserves-neighborhood-right-sim-Pseudometric-Space M y~y' d x'
- ( preserves-neighborhood-left-sim-Pseudometric-Space
+ preserves-neighborhoods-right-sim-Pseudometric-Space M y~y' d x'
+ ( preserves-neighborhoods-left-sim-Pseudometric-Space
( M)
( x~x')
( d)
( y)
( d⟨x,y⟩))
- reflects-neighborhood-map-metric-quotient-Pseudometric-Space :
+ reflects-neighborhoods-map-metric-quotient-Pseudometric-Space :
(d : ℚ⁺) (x y : type-Pseudometric-Space M) →
neighborhood-metric-quotient-Pseudometric-Space
( M)
@@ -439,7 +450,7 @@ module _
( map-metric-quotient-Pseudometric-Space M x)
( map-metric-quotient-Pseudometric-Space M y) →
neighborhood-Pseudometric-Space M d x y
- reflects-neighborhood-map-metric-quotient-Pseudometric-Space
+ reflects-neighborhoods-map-metric-quotient-Pseudometric-Space
d x y Nxy =
Nxy
( map-subtype-metric-quotient-Pseudometric-Space M x)
@@ -451,8 +462,8 @@ module _
( pseudometric-metric-quotient-Pseudometric-Space M)
( map-metric-quotient-Pseudometric-Space M)
is-isometry-map-metric-quotient-Pseudometric-Space d x y =
- ( preserves-neighborhood-map-metric-quotient-Pseudometric-Space d x y ,
- reflects-neighborhood-map-metric-quotient-Pseudometric-Space d x y)
+ ( preserves-neighborhoods-map-metric-quotient-Pseudometric-Space d x y ,
+ reflects-neighborhoods-map-metric-quotient-Pseudometric-Space d x y)
```
### The isometry from a pseudometric space to its quotient metric space
@@ -758,7 +769,7 @@ module _
( f))
abstract
- preserves-neighborhood-map-isometry-metric-quotient-Pseudometric-Space :
+ preserves-neighborhoods-map-isometry-metric-quotient-Pseudometric-Space :
(d : ℚ⁺) →
(x y : type-metric-quotient-Pseudometric-Space A) →
neighborhood-metric-quotient-Pseudometric-Space
@@ -771,7 +782,7 @@ module _
( d)
( map-isometry-metric-quotient-Pseudometric-Space x)
( map-isometry-metric-quotient-Pseudometric-Space y)
- preserves-neighborhood-map-isometry-metric-quotient-Pseudometric-Space =
+ preserves-neighborhoods-map-isometry-metric-quotient-Pseudometric-Space =
is-short-map-short-function-metric-quotient-Pseudometric-Space
( A)
( B)
@@ -780,7 +791,7 @@ module _
( pseudometric-Metric-Space B)
( f))
- reflects-neighborhood-map-isometry-metric-quotient-Pseudometric-Space :
+ reflects-neighborhoods-map-isometry-metric-quotient-Pseudometric-Space :
(d : ℚ⁺) →
(x y : type-metric-quotient-Pseudometric-Space A) →
neighborhood-Metric-Space
@@ -793,9 +804,9 @@ module _
( d)
( x)
( y)
- reflects-neighborhood-map-isometry-metric-quotient-Pseudometric-Space
+ reflects-neighborhoods-map-isometry-metric-quotient-Pseudometric-Space
d X Y N⟨fX,fY⟩ (x , x∈X) (y , y∈Y) =
- reflects-neighborhood-map-isometry-Pseudometric-Space
+ reflects-neighborhoods-map-isometry-Pseudometric-Space
( A)
( pseudometric-Metric-Space B)
( f)
@@ -814,11 +825,11 @@ module _
( B)
( map-isometry-metric-quotient-Pseudometric-Space)
is-isometry-map-isometry-metric-quotient-Pseudometric-Space d x y =
- ( preserves-neighborhood-map-isometry-metric-quotient-Pseudometric-Space
+ ( preserves-neighborhoods-map-isometry-metric-quotient-Pseudometric-Space
( d)
( x)
( y) ,
- reflects-neighborhood-map-isometry-metric-quotient-Pseudometric-Space
+ reflects-neighborhoods-map-isometry-metric-quotient-Pseudometric-Space
( d)
( x)
( y))
diff --git a/src/metric-spaces/metric-space-of-cauchy-approximations-metric-spaces.lagda.md b/src/metric-spaces/metric-space-of-cauchy-approximations-metric-spaces.lagda.md
index 85dc63e6e8..bf3bf5b299 100644
--- a/src/metric-spaces/metric-space-of-cauchy-approximations-metric-spaces.lagda.md
+++ b/src/metric-spaces/metric-space-of-cauchy-approximations-metric-spaces.lagda.md
@@ -17,6 +17,7 @@ open import foundation.involutions
open import foundation.subtypes
open import foundation.universe-levels
+open import metric-spaces.action-on-cauchy-approximations-short-maps-metric-spaces
open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.dependent-products-metric-spaces
open import metric-spaces.equality-of-metric-spaces
@@ -92,24 +93,24 @@ module _
(f : short-function-Metric-Space A B)
where
- is-short-map-short-function-cauchy-approximation-Metric-Space :
+ is-short-map-cauchy-approximation-short-function-Metric-Space :
is-short-function-Metric-Space
( metric-space-of-cauchy-approximations-Metric-Space A)
( metric-space-of-cauchy-approximations-Metric-Space B)
- ( map-short-function-cauchy-approximation-Metric-Space A B f)
- is-short-map-short-function-cauchy-approximation-Metric-Space ε x y Nxy δ =
+ ( map-cauchy-approximation-short-function-Metric-Space A B f)
+ is-short-map-cauchy-approximation-short-function-Metric-Space ε x y Nxy δ =
is-short-map-short-function-Metric-Space A B f ε
( map-cauchy-approximation-Metric-Space A x δ)
( map-cauchy-approximation-Metric-Space A y δ)
( Nxy δ)
- short-map-short-function-cauchy-approximation-Metric-Space :
+ short-map-cauchy-approximation-short-function-Metric-Space :
short-function-Metric-Space
( metric-space-of-cauchy-approximations-Metric-Space A)
( metric-space-of-cauchy-approximations-Metric-Space B)
- short-map-short-function-cauchy-approximation-Metric-Space =
- map-short-function-cauchy-approximation-Metric-Space A B f ,
- is-short-map-short-function-cauchy-approximation-Metric-Space
+ short-map-cauchy-approximation-short-function-Metric-Space =
+ map-cauchy-approximation-short-function-Metric-Space A B f ,
+ is-short-map-cauchy-approximation-short-function-Metric-Space
```
### Swapping the arguments of a Cauchy approximation of Cauchy approximations produces a Cauchy approximation
diff --git a/src/metric-spaces/precategory-of-metric-spaces-and-isometries.lagda.md b/src/metric-spaces/precategory-of-metric-spaces-and-isometries.lagda.md
index ba315c5ba8..04989c2bea 100644
--- a/src/metric-spaces/precategory-of-metric-spaces-and-isometries.lagda.md
+++ b/src/metric-spaces/precategory-of-metric-spaces-and-isometries.lagda.md
@@ -55,7 +55,7 @@ module _
( Metric-Space l1 l2)
( set-isometry-Metric-Space)
( λ {A B C} → comp-isometry-Metric-Space A B C)
- ( isometry-id-Metric-Space)
+ ( id-isometry-Metric-Space)
( λ {A B C D} → associative-comp-isometry-Metric-Space A B C D)
( λ {A B} → left-unit-law-comp-isometry-Metric-Space A B)
( λ {A B} → right-unit-law-comp-isometry-Metric-Space A B)
diff --git a/src/metric-spaces/precategory-of-metric-spaces-and-short-functions.lagda.md b/src/metric-spaces/precategory-of-metric-spaces-and-short-functions.lagda.md
index 6d3251395d..c494f32b3d 100644
--- a/src/metric-spaces/precategory-of-metric-spaces-and-short-functions.lagda.md
+++ b/src/metric-spaces/precategory-of-metric-spaces-and-short-functions.lagda.md
@@ -56,7 +56,7 @@ module _
( Metric-Space l1 l2)
( set-short-function-Metric-Space)
( λ {A B C} → comp-short-function-Metric-Space A B C)
- ( short-id-Metric-Space)
+ ( id-short-function-Metric-Space)
( λ {A B C D} → associative-comp-short-function-Metric-Space A B C D)
( λ {A B} → left-unit-law-comp-short-function-Metric-Space A B)
( λ {A B} → right-unit-law-comp-short-function-Metric-Space A B)
@@ -149,7 +149,7 @@ module _
( B)
( f)
( short-inverse))
- ( short-id-Metric-Space B)
+ ( id-short-function-Metric-Space B)
( is-section-map-inv-is-equiv E)) ,
( eq-htpy-map-short-function-Metric-Space
( A)
@@ -160,7 +160,7 @@ module _
( A)
( short-inverse)
( f))
- ( short-id-Metric-Space A)
+ ( id-short-function-Metric-Space A)
( is-retraction-map-inv-is-equiv E)))
where
diff --git a/src/metric-spaces/rational-cauchy-approximations.lagda.md b/src/metric-spaces/rational-cauchy-approximations.lagda.md
index d5f5d1b432..8e4ef2260e 100644
--- a/src/metric-spaces/rational-cauchy-approximations.lagda.md
+++ b/src/metric-spaces/rational-cauchy-approximations.lagda.md
@@ -19,6 +19,7 @@ open import foundation.propositions
open import foundation.subtypes
open import foundation.universe-levels
+open import metric-spaces.action-on-cauchy-approximations-short-maps-metric-spaces
open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.complete-metric-spaces
open import metric-spaces.convergent-cauchy-approximations-metric-spaces
@@ -94,7 +95,7 @@ real-limit-cauchy-approximation-ℚ : cauchy-approximation-ℚ → ℝ lzero
real-limit-cauchy-approximation-ℚ f =
limit-cauchy-approximation-Complete-Metric-Space
( complete-metric-space-ℝ lzero)
- ( map-short-function-cauchy-approximation-Metric-Space
+ ( map-cauchy-approximation-short-function-Metric-Space
( metric-space-ℚ)
( metric-space-ℝ lzero)
( short-isometry-Metric-Space
diff --git a/src/metric-spaces/short-functions-metric-spaces.lagda.md b/src/metric-spaces/short-functions-metric-spaces.lagda.md
index 64e55931bc..e0cb7d72f2 100644
--- a/src/metric-spaces/short-functions-metric-spaces.lagda.md
+++ b/src/metric-spaces/short-functions-metric-spaces.lagda.md
@@ -140,9 +140,9 @@ module _
is-short-id-Pseudometric-Space
( pseudometric-Metric-Space A)
- short-id-Metric-Space : short-function-Metric-Space A A
- short-id-Metric-Space =
- short-id-Pseudometric-Space (pseudometric-Metric-Space A)
+ id-short-function-Metric-Space : short-function-Metric-Space A A
+ id-short-function-Metric-Space =
+ id-short-function-Pseudometric-Space (pseudometric-Metric-Space A)
```
### Equality of short functions between metric spaces is characterized by homotopy of their carrier maps
@@ -216,7 +216,7 @@ module _
left-unit-law-comp-short-function-Metric-Space :
( comp-short-function-Metric-Space A B B
- ( short-id-Metric-Space B)
+ ( id-short-function-Metric-Space B)
( f)) =
( f)
left-unit-law-comp-short-function-Metric-Space =
@@ -228,7 +228,7 @@ module _
right-unit-law-comp-short-function-Metric-Space :
( comp-short-function-Metric-Space A A B
( f)
- ( short-id-Metric-Space A)) =
+ ( id-short-function-Metric-Space A)) =
( f)
right-unit-law-comp-short-function-Metric-Space =
right-unit-law-comp-short-function-Pseudometric-Space
diff --git a/src/metric-spaces/short-functions-pseudometric-spaces.lagda.md b/src/metric-spaces/short-functions-pseudometric-spaces.lagda.md
index 2075b6e100..c4e262d3a3 100644
--- a/src/metric-spaces/short-functions-pseudometric-spaces.lagda.md
+++ b/src/metric-spaces/short-functions-pseudometric-spaces.lagda.md
@@ -116,9 +116,10 @@ module _
is-short-function-Pseudometric-Space A A (id-Pseudometric-Space A)
is-short-id-Pseudometric-Space d x y H = H
- short-id-Pseudometric-Space : short-function-Pseudometric-Space A A
- short-id-Pseudometric-Space =
- id-Pseudometric-Space A , is-short-id-Pseudometric-Space
+ id-short-function-Pseudometric-Space :
+ short-function-Pseudometric-Space A A
+ id-short-function-Pseudometric-Space =
+ ( id-Pseudometric-Space A , is-short-id-Pseudometric-Space)
```
### Equality of short functions between pseudometric spaces is characterized by homotopy of their carrier maps
@@ -192,7 +193,7 @@ module _
left-unit-law-comp-short-function-Pseudometric-Space :
( comp-short-function-Pseudometric-Space A B B
- ( short-id-Pseudometric-Space B)
+ ( id-short-function-Pseudometric-Space B)
( f)) =
( f)
left-unit-law-comp-short-function-Pseudometric-Space =
@@ -203,7 +204,7 @@ module _
( A)
( B)
( B)
- ( short-id-Pseudometric-Space B)
+ ( id-short-function-Pseudometric-Space B)
( f))
( f)
( λ x → refl)
@@ -211,7 +212,7 @@ module _
right-unit-law-comp-short-function-Pseudometric-Space :
( comp-short-function-Pseudometric-Space A A B
( f)
- ( short-id-Pseudometric-Space A)) =
+ ( id-short-function-Pseudometric-Space A)) =
( f)
right-unit-law-comp-short-function-Pseudometric-Space =
eq-htpy-map-short-function-Pseudometric-Space
@@ -223,7 +224,7 @@ module _
( A)
( B)
( f)
- ( short-id-Pseudometric-Space A))
+ ( id-short-function-Pseudometric-Space A))
( λ x → refl)
```
@@ -295,7 +296,7 @@ module _
is-isometry-Pseudometric-Space A B f →
is-short-function-Pseudometric-Space A B f
is-short-is-isometry-Pseudometric-Space I =
- preserves-neighborhood-map-isometry-Pseudometric-Space A B (f , I)
+ preserves-neighborhoods-map-isometry-Pseudometric-Space A B (f , I)
```
### The embedding of isometries of pseudometric spaces into short maps
diff --git a/src/metric-spaces/similarity-of-elements-pseudometric-spaces.lagda.md b/src/metric-spaces/similarity-of-elements-pseudometric-spaces.lagda.md
index f9caa041d2..6a249158e4 100644
--- a/src/metric-spaces/similarity-of-elements-pseudometric-spaces.lagda.md
+++ b/src/metric-spaces/similarity-of-elements-pseudometric-spaces.lagda.md
@@ -22,6 +22,7 @@ open import foundation.propositions
open import foundation.transport-along-identifications
open import foundation.universe-levels
+open import metric-spaces.isometries-pseudometric-spaces
open import metric-spaces.pseudometric-spaces
open import metric-spaces.rational-neighborhood-relations
open import metric-spaces.short-functions-pseudometric-spaces
@@ -172,13 +173,13 @@ module _
where
abstract
- preserves-neighborhood-left-sim-Pseudometric-Space :
+ preserves-neighborhoods-left-sim-Pseudometric-Space :
{ x y : type-Pseudometric-Space A} →
( sim-Pseudometric-Space A x y) →
( d : ℚ⁺) (z : type-Pseudometric-Space A) →
neighborhood-Pseudometric-Space A d x z →
neighborhood-Pseudometric-Space A d y z
- preserves-neighborhood-left-sim-Pseudometric-Space {x} {y} x≍y d z Nxz =
+ preserves-neighborhoods-left-sim-Pseudometric-Space {x} {y} x≍y d z Nxz =
saturated-neighborhood-Pseudometric-Space
( A)
( d)
@@ -203,46 +204,46 @@ module _
( y)
( x≍y δ))))
- preserves-neighborhood-right-sim-Pseudometric-Space :
+ preserves-neighborhoods-right-sim-Pseudometric-Space :
{ x y : type-Pseudometric-Space A} →
( sim-Pseudometric-Space A x y) →
( d : ℚ⁺) (z : type-Pseudometric-Space A) →
neighborhood-Pseudometric-Space A d z x →
neighborhood-Pseudometric-Space A d z y
- preserves-neighborhood-right-sim-Pseudometric-Space {x} {y} x≍y d z Nzx =
+ preserves-neighborhoods-right-sim-Pseudometric-Space {x} {y} x≍y d z Nzx =
symmetric-neighborhood-Pseudometric-Space A d y z
- ( preserves-neighborhood-left-sim-Pseudometric-Space x≍y d z
+ ( preserves-neighborhoods-left-sim-Pseudometric-Space x≍y d z
( symmetric-neighborhood-Pseudometric-Space A d z x Nzx))
- preserves-neighborhood-sim-Pseudometric-Space :
+ preserves-neighborhoods-sim-Pseudometric-Space :
{x x' y y' : type-Pseudometric-Space A} →
sim-Pseudometric-Space A x x' →
sim-Pseudometric-Space A y y' →
(d : ℚ⁺) →
neighborhood-Pseudometric-Space A d x y →
neighborhood-Pseudometric-Space A d x' y'
- preserves-neighborhood-sim-Pseudometric-Space
+ preserves-neighborhoods-sim-Pseudometric-Space
{x} {x'} {y} {y'} x~x' y~y' d Nxy =
- preserves-neighborhood-left-sim-Pseudometric-Space
+ preserves-neighborhoods-left-sim-Pseudometric-Space
( x~x')
( d)
( y')
- ( preserves-neighborhood-right-sim-Pseudometric-Space
+ ( preserves-neighborhoods-right-sim-Pseudometric-Space
( y~y')
( d)
( x)
( Nxy))
- reflects-neighborhood-sim-Pseudometric-Space :
+ reflects-neighborhoods-sim-Pseudometric-Space :
{x x' y y' : type-Pseudometric-Space A} →
sim-Pseudometric-Space A x x' →
sim-Pseudometric-Space A y y' →
(d : ℚ⁺) →
neighborhood-Pseudometric-Space A d x' y' →
neighborhood-Pseudometric-Space A d x y
- reflects-neighborhood-sim-Pseudometric-Space
+ reflects-neighborhoods-sim-Pseudometric-Space
{x} {x'} {y} {y'} x~x' y~y' =
- preserves-neighborhood-sim-Pseudometric-Space
+ preserves-neighborhoods-sim-Pseudometric-Space
( inv-sim-Pseudometric-Space A x~x')
( inv-sim-Pseudometric-Space A y~y')
@@ -254,8 +255,8 @@ module _
neighborhood-Pseudometric-Space A d y z)
same-neighbors-iff-sim-Pseudometric-Space =
( λ x≍y d z →
- ( preserves-neighborhood-left-sim-Pseudometric-Space x≍y d z) ,
- ( preserves-neighborhood-left-sim-Pseudometric-Space
+ ( preserves-neighborhoods-left-sim-Pseudometric-Space x≍y d z) ,
+ ( preserves-neighborhoods-left-sim-Pseudometric-Space
( inv-sim-Pseudometric-Space A x≍y)
( d)
( z))) ,
@@ -314,15 +315,46 @@ module _
( A : Pseudometric-Space l1 l2)
( B : Pseudometric-Space l1' l2')
( f : short-function-Pseudometric-Space A B)
- where
+ where abstract
+
+ preserves-sim-map-short-function-Pseudometric-Space :
+ ( x y : type-Pseudometric-Space A) →
+ ( sim-Pseudometric-Space A x y) →
+ ( sim-Pseudometric-Space B
+ ( map-short-function-Pseudometric-Space A B f x)
+ ( map-short-function-Pseudometric-Space A B f y))
+ preserves-sim-map-short-function-Pseudometric-Space x y x~y d =
+ is-short-map-short-function-Pseudometric-Space A B f d x y (x~y d)
+```
- abstract
- preserves-sim-map-short-function-Pseudometric-Space :
- ( x y : type-Pseudometric-Space A) →
- ( sim-Pseudometric-Space A x y) →
- ( sim-Pseudometric-Space B
- ( map-short-function-Pseudometric-Space A B f x)
- ( map-short-function-Pseudometric-Space A B f y))
- preserves-sim-map-short-function-Pseudometric-Space x y x~y d =
- is-short-map-short-function-Pseudometric-Space A B f d x y (x~y d)
+### Isometries between pseudometric spaces preserve and reflect similarity
+
+```agda
+module _
+ { l1 l2 l1' l2' : Level}
+ ( A : Pseudometric-Space l1 l2)
+ ( B : Pseudometric-Space l1' l2')
+ ( f : isometry-Pseudometric-Space A B)
+ where abstract
+
+ preserves-sim-map-isometry-Pseudometric-Space :
+ ( x y : type-Pseudometric-Space A) →
+ ( sim-Pseudometric-Space A x y) →
+ ( sim-Pseudometric-Space B
+ ( map-isometry-Pseudometric-Space A B f x)
+ ( map-isometry-Pseudometric-Space A B f y))
+ preserves-sim-map-isometry-Pseudometric-Space =
+ preserves-sim-map-short-function-Pseudometric-Space
+ ( A)
+ ( B)
+ ( short-isometry-Pseudometric-Space A B f)
+
+ reflects-sim-map-isometry-Pseudometric-Space :
+ ( x y : type-Pseudometric-Space A) →
+ ( sim-Pseudometric-Space B
+ ( map-isometry-Pseudometric-Space A B f x)
+ ( map-isometry-Pseudometric-Space A B f y)) →
+ ( sim-Pseudometric-Space A x y)
+ reflects-sim-map-isometry-Pseudometric-Space x y fx~fy d =
+ reflects-neighborhoods-map-isometry-Pseudometric-Space A B f d x y (fx~fy d)
```
diff --git a/src/real-numbers/proper-closed-intervals-real-numbers.lagda.md b/src/real-numbers/proper-closed-intervals-real-numbers.lagda.md
index 21f5ab7e36..86f77218aa 100644
--- a/src/real-numbers/proper-closed-intervals-real-numbers.lagda.md
+++ b/src/real-numbers/proper-closed-intervals-real-numbers.lagda.md
@@ -20,6 +20,7 @@ open import foundation.subtypes
open import foundation.transport-along-identifications
open import foundation.universe-levels
+open import metric-spaces.action-on-cauchy-approximations-short-maps-metric-spaces
open import metric-spaces.cauchy-approximations-metric-spaces
open import metric-spaces.closed-subsets-metric-spaces
open import metric-spaces.complete-metric-spaces
@@ -221,7 +222,7 @@ abstract
( metric-space-ℝ l)
( subtype-proper-closed-interval-ℝ l [a,b])
approx-clamp-add =
- map-short-function-cauchy-approximation-Metric-Space
+ map-cauchy-approximation-short-function-Metric-Space
( metric-space-ℚ)
( metric-space-proper-closed-interval-ℝ l [a,b])
( short-clamp-add)
@@ -243,7 +244,7 @@ abstract
tr
( is-limit-cauchy-approximation-Metric-Space
( metric-space-ℝ l)
- ( map-short-function-cauchy-approximation-Metric-Space
+ ( map-cauchy-approximation-short-function-Metric-Space
( metric-space-proper-closed-interval-ℝ l [a,b])
( metric-space-ℝ l)
( short-inclusion)
@@ -256,7 +257,7 @@ abstract
by ap-max-ℝ refl (eq-sim-ℝ (right-leq-left-min-ℝ x≤b))
= x
by eq-sim-ℝ (left-leq-right-max-ℝ a≤x))
- ( preserves-limit-cauchy-approximation-map-short-function-Metric-Space
+ ( preserves-limit-map-cauchy-approximation-short-function-Metric-Space
( metric-space-ℚ)
( metric-space-ℝ l)
( comp-short-function-Metric-Space
@@ -304,7 +305,7 @@ abstract
( metric-space-ℝ l)
( subtype-proper-closed-interval-ℝ l [a,b])
approx-clamp-diff =
- map-short-function-cauchy-approximation-Metric-Space
+ map-cauchy-approximation-short-function-Metric-Space
( metric-space-ℚ)
( metric-space-proper-closed-interval-ℝ l [a,b])
( short-clamp-diff)
@@ -326,7 +327,7 @@ abstract
tr
( is-limit-cauchy-approximation-Metric-Space
( metric-space-ℝ l)
- ( map-short-function-cauchy-approximation-Metric-Space
+ ( map-cauchy-approximation-short-function-Metric-Space
( metric-space-proper-closed-interval-ℝ l [a,b])
( metric-space-ℝ l)
( short-inclusion)
@@ -340,7 +341,7 @@ abstract
ap-max-ℝ refl (eq-sim-ℝ (right-leq-left-min-ℝ x≤b))
= x
by eq-sim-ℝ (left-leq-right-max-ℝ a≤x))
- ( preserves-limit-cauchy-approximation-map-short-function-Metric-Space
+ ( preserves-limit-map-cauchy-approximation-short-function-Metric-Space
( metric-space-ℚ)
( metric-space-ℝ l)
( comp-short-function-Metric-Space