New note

Author: localhost433

notes/courses/LING-UA-1/11-12-semantics.md

@@ -0,0 +1,66 @@
+---
+title: Semantics
+date: 2025-06-10/11
+---
+
+# Semantics
+
+## Semantics vs. Pragmatics
+
+## Defining semantics
+Hypothesis 1: meanings are paraphrases (circular)  
+Hypothesis 2: Meanings are concepts and ideas (Different ideas in different people's mind, hard to represent some words.)  
+Hypothesis 3: Meanings are out in the world.
+
+## Sentence meanings and truth conditions
+
+### Truth is relative
+Given a certain condition, we can judge the truth value of a sentence.  
+We only need to know *what the world should be like* for a sentence to actually be true or false.
+
+### Possible worlds
+For each way the world *could have been*, there is a distinct possible world.  
+Only talk about *logically* possible ways that would have turned out.  
+Ex. $2 + 2 \neq 5$ (I was thinking this maybe could be true in a quaternary system, but then I realized 5 isn't even a defined digit under that. There is only $2_4 + 2_4 = 10_4$)
+
+### Connectives
+- negation *not* reverses the truth.
+- logical connectives *and* require both conjuncts to be true.
+- logical connectives *or* require one of the two conjuncts to be true.
+
+## Composing meanings
+### Establishing truth conditions
+Meaning of a sentence is its truth conditions.
+- Determining the meaning of a sentence by the meanings of the words it contains and the way they are combined. This is called the **principle of compositionality**.
+- There is an order of operations establishing the conditions.
+
+(The reason I think that there's the logical aspect, because the word in languages doesn't have a connection to it's meaning. So there is the need of building the logic constructively from ground up, not using established languages)
+
+### Common semantic building blocks
+- Names (proper nouns) refer to specific individuals in the world (**referent**)
+- Common nouns refer to the *collection* of individuals in the world.
+- Verb phrases that combine with a subject noun to form a sentence are called **predicates**.
+    - Under what conditions it applies to any given individual.
+    - What the world must be like for it to apply to any given individual.
+    - In what kinds of logically possible situations it would be possible.
+
+### Set theory
+Venn diagrams to model the set of individuals.  
+**Inclusive** and **Exclusive or**.  
+but is logically equivalent to and, but it conveys an extra meaning of unexpectedness or contrast.
+
+### Quantifiers
+To relate predicates to other predicates, examples:
+- every (subset)
+- some (non-empty intersection)
+- no (no intersection)
+- numerals (exact quantity of the shared elements)
+
+## Entailment
+- When one sentence follows from another. 
+  - (Implication that are one/two directional)
+  - A formal definition of being **synonymous** (iff).
+- When sentences are contradictory.
+  - a formal definition of being **contradictions**
+
+Relation of entailment is given just by the meaning of a sentence, independent of context. However, in actual conversation speakers often rely on context when communicating. More related to pragmatics.

notes/courses/LING-UA-1/index.json

@@ -28,4 +28,10 @@
         "title": "08/09/10 - Syntax",
         "date": "2025-06-02/03/04"
     }
+    ,
+    {
+        "slug": "11-12-semantics",
+        "title": "11/12 - Semantics",
+        "date": "2025-06-10/11"
+    }
 ]