diff --git a/Compiler/FrontEnd/DAE.mo b/Compiler/FrontEnd/DAE.mo
index fb9616f5f3..2564a1f12b 100644
--- a/Compiler/FrontEnd/DAE.mo
+++ b/Compiler/FrontEnd/DAE.mo
@@ -1345,17 +1345,17 @@ uniontype Exp "Expressions
     Exp exp;
   end LUNARY;
 
-  record RELATION "Relation, e.g. a <= 0
-    Index contains normal an Integer for every ZeroCrossing
-    but if Relation is in algorithm with for loop the iterator and the range
-    of static iterator is needed for codegen"
+  record RELATION "Relation, e.g. a <= 0"
     Exp exp1;
     Operator operator;
     Exp exp2;
-    Integer index;
-    Option<tuple<Exp,Integer,Integer>> optionExpisASUB;
   end RELATION;
 
+  record ZEROCROSSING "Backend expression for zero crossing"
+    Exp exp;
+    Integer index;
+  end ZEROCROSSING;
+
   record IFEXP "If expressions"
     Exp expCond;
     Exp expThen;
diff --git a/Compiler/Template/CodegenAdevs.tpl b/Compiler/Template/CodegenAdevs.tpl
index 1026c77717..05db57b3df 100644
--- a/Compiler/Template/CodegenAdevs.tpl
+++ b/Compiler/Template/CodegenAdevs.tpl
@@ -3611,6 +3611,7 @@ template daeExp(Exp exp, Context context, Text &preExp /*BUFP*/, Text &varDecls
   case e as LBINARY(__)         then daeExpLbinary(e, context, &preExp /*BUFC*/, &varDecls /*BUFD*/)
   case e as LUNARY(__)          then daeExpLunary(e, context, &preExp /*BUFC*/, &varDecls /*BUFD*/)
   case e as RELATION(__)        then daeExpRelation(e, context, &preExp /*BUFC*/, &varDecls /*BUFD*/)
+  case e as ZEROCROSSING(__)    then daeExpZeroCrossingSim(e, index, context, &preExp /*BUFC*/, &varDecls /*BUFD*/)
   case e as IFEXP(__)           then daeExpIf(e, context, &preExp /*BUFC*/, &varDecls /*BUFD*/)
   case e as CALL(__)            then daeExpCall(e, context, &preExp /*BUFC*/, &varDecls /*BUFD*/)
   case e as ARRAY(__)           then daeExpArray(e, context, &preExp /*BUFC*/, &varDecls /*BUFD*/)
@@ -3968,23 +3969,22 @@ case rel as RELATION(__) then
     else "daeExpRelation:ERR"
 end daeExpRelation;
 
-
-template daeExpRelationSim(Exp exp, Context context, Text &preExp /*BUFP*/,
+template daeExpZeroCrossingSim(Exp exp, Integer index, Context context, Text &preExp /*BUFP*/,
                            Text &varDecls /*BUFP*/)
  "Helper to daeExpRelation."
 ::=
 match exp
-case rel as RELATION(__) then
+case zc as ZEROCROSSING(__) then
   match context
   case SIMULATION_CONTEXT(genDiscrete=false) then
-     match rel.optionExpisASUB
-     case NONE() then
-        let e1 = daeExp(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-        let e2 = daeExp(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-        let res = tempDecl("modelica_boolean", &varDecls /*BUFC*/)
-        match rel.operator
+    match zc.exp
+       case rel as RELATION(__)
+         let e1 = daeExp(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
+         let e2 = daeExp(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
+         let res = tempDecl("modelica_boolean", &varDecls /*BUFC*/)
+       match rel.operator
         case LESS(__) then
-          let &preExp += 'ADEVS_RELATIONTOZC(<%res%>, <%e1%>, <%e2%>, <%rel.index%>,<);<%\n%>'
+          let &preExp += 'ADEVS_RELATIONTOZC(<%res%>, <%e1%>, <%e2%>, <%.index%>,<);<%\n%>'
           res
         case LESSEQ(__) then
           let &preExp += 'ADEVS_RELATIONTOZC(<%res%>, <%e1%>, <%e2%>, <%rel.index%>,<=);<%\n%>'
diff --git a/Compiler/Template/CodegenCFunctions.tpl b/Compiler/Template/CodegenCFunctions.tpl
index db313ebdfa..db8ec1bd22 100644
--- a/Compiler/Template/CodegenCFunctions.tpl
+++ b/Compiler/Template/CodegenCFunctions.tpl
@@ -4323,6 +4323,7 @@ end getTempDeclMatchOutputName;
   case e as LBINARY(__)         then daeExpLbinary(e, context, &preExp, &varDecls, &auxFunction)
   case e as LUNARY(__)          then daeExpLunary(e, context, &preExp, &varDecls, &auxFunction)
   case e as RELATION(__)        then daeExpRelation(e, context, &preExp, &varDecls, &auxFunction)
+  case e as ZEROCROSSING(__)    then daeExpZeroCrossing(e, context, &preExp, &varDecls, &auxFunction)
   case e as IFEXP(__)           then daeExpIf(e, context, &preExp, &varDecls, &auxFunction)
   case e as CALL(__)            then daeExpCall(e, context, &preExp, &varDecls, &auxFunction)
   case e as RECORD(__)          then daeExpRecord(e, context, &preExp, &varDecls, &auxFunction)
@@ -5132,15 +5133,6 @@ template daeExpRelation(Exp exp, Context context, Text &preExp,
 ::=
 match exp
 case rel as RELATION(__) then
-  let &varDecls2 = buffer ""
-  let &preExp2 = buffer ""
-  let simRel = daeExpRelationSim(rel, context, &preExp2, &varDecls2, &auxFunction)
-  if simRel then
-    /* Don't add the allocated temp-var unless it is used */
-    let &varDecls += varDecls2
-    let &preExp += preExp2
-    simRel
-  else
     let e1 = daeExp(rel.exp1, context, &preExp, &varDecls, &auxFunction)
     let e2 = daeExp(rel.exp2, context, &preExp, &varDecls, &auxFunction)
     match rel.operator
@@ -5185,175 +5177,21 @@ case rel as RELATION(__) then
     else error(sourceInfo(), 'daeExpRelation <%ExpressionDumpTpl.dumpExp(exp,"\"")%>')
 end daeExpRelation;
 
-
-
-template daeExpRelationSim(Exp exp, Context context, Text &preExp,
+template daeExpZeroCrossing(Exp exp, Context context, Text &preExp,
                            Text &varDecls, Text &auxFunction)
  "Helper to daeExpRelation."
 ::=
 match exp
-case rel as RELATION(__) then
+case zc as ZEROCROSSING(__) then
   match context
   case SIMULATION_CONTEXT(__) then
-    match rel.optionExpisASUB
-    case NONE() then
-      let e1 = daeExp(rel.exp1, context, &preExp, &varDecls, &auxFunction)
-      let e2 = daeExp(rel.exp2, context, &preExp, &varDecls, &auxFunction)
-      let res = tempDecl("modelica_boolean", &varDecls)
-      if intEq(rel.index,-1) then
-        match rel.operator
-        case LESS(__) then
-          let &preExp += '<%res%> = Less(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case LESSEQ(__) then
-          let &preExp += '<%res%> = LessEq(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case GREATER(__) then
-          let &preExp += '<%res%> = Greater(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case GREATEREQ(__) then
-          let &preExp += '<%res%> = GreaterEq(<%e1%>,<%e2%>);<%\n%>'
-          res
-        end match
-      else
-        let isReal = if isRealType(typeof(rel.exp1)) then (if isRealType(typeof(rel.exp2)) then 'true' else '') else ''
-        let hysteresisfunction = if isReal then 'RELATIONHYSTERESIS' else 'RELATION'
-        match rel.operator
-        case LESS(__) then
-          let &preExp += '<%hysteresisfunction%>(<%res%>, <%e1%>, <%e2%>, <%rel.index%>, Less);<%\n%>'
-          res
-        case LESSEQ(__) then
-          let &preExp += '<%hysteresisfunction%>(<%res%>, <%e1%>, <%e2%>, <%rel.index%>, LessEq);<%\n%>'
-          res
-        case GREATER(__) then
-          let &preExp += '<%hysteresisfunction%>(<%res%>, <%e1%>, <%e2%>, <%rel.index%>, Greater);<%\n%>'
-          res
-        case GREATEREQ(__) then
-          let &preExp += '<%hysteresisfunction%>(<%res%>, <%e1%>, <%e2%>, <%rel.index%>, GreaterEq);<%\n%>'
-          res
-        end match
-    case SOME((exp,i,j)) then
-      let e1 = daeExp(rel.exp1, context, &preExp, &varDecls, &auxFunction)
-      let e2 = daeExp(rel.exp2, context, &preExp, &varDecls, &auxFunction)
-      let iterator = daeExp(exp, context, &preExp, &varDecls, &auxFunction)
-      let res = tempDecl("modelica_boolean", &varDecls)
-      if intEq(rel.index,-1) then
-        match rel.operator
-        case LESS(__) then
-          let &preExp += '<%res%> = Less(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case LESSEQ(__) then
-          let &preExp += '<%res%> = LessEq(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case GREATER(__) then
-          let &preExp += '<%res%> = Greater(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case GREATEREQ(__) then
-          let &preExp += '<%res%> = GreaterEq(<%e1%>,<%e2%>);<%\n%>'
-          res
-        end match
-      else
-        let isReal = if isRealType(typeof(rel.exp1)) then (if isRealType(typeof(rel.exp2)) then 'true' else '') else ''
-        let hysteresisfunction = if isReal then 'RELATIONHYSTERESIS' else 'RELATION'
-        match rel.operator
-        case LESS(__) then
-          let &preExp += '<%hysteresisfunction%>(<%res%>, <%e1%>, <%e2%>, <%rel.index%> + (<%iterator%> - <%i%>)/<%j%>, Less);<%\n%>'
-          res
-        case LESSEQ(__) then
-          let &preExp += '<%hysteresisfunction%>(<%res%>, <%e1%>, <%e2%>, <%rel.index%> + (<%iterator%> - <%i%>)/<%j%>, LessEq);<%\n%>'
-          res
-        case GREATER(__) then
-          let &preExp += '<%hysteresisfunction%>(<%res%>, <%e1%>, <%e2%>, <%rel.index%> + (<%iterator%> - <%i%>)/<%j%>, Greater);<%\n%>'
-          res
-        case GREATEREQ(__) then
-          let &preExp += '<%hysteresisfunction%>(<%res%>, <%e1%>, <%e2%>, <%rel.index%> + (<%iterator%> - <%i%>)/<%j%>, GreaterEq);<%\n%>'
-          res
-        end match
-    end match
-  case ZEROCROSSINGS_CONTEXT(__) then
-    match rel.optionExpisASUB
-    case NONE() then
-      let e1 = daeExp(rel.exp1, context, &preExp, &varDecls, &auxFunction)
-      let e2 = daeExp(rel.exp2, context, &preExp, &varDecls, &auxFunction)
-      let res = tempDecl("modelica_boolean", &varDecls)
-      if intEq(rel.index,-1) then
-        match rel.operator
-        case LESS(__) then
-          let &preExp += '<%res%> = Less(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case LESSEQ(__) then
-          let &preExp += '<%res%> = LessEq(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case GREATER(__) then
-          let &preExp += '<%res%> = Greater(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case GREATEREQ(__) then
-          let &preExp += '<%res%> = GreaterEq(<%e1%>,<%e2%>);<%\n%>'
-          res
-        end match
-      else
-        let isReal = if isRealType(typeof(rel.exp1)) then (if isRealType(typeof(rel.exp2)) then 'true' else '') else ''
-        match rel.operator
-        case LESS(__) then
-          let hysteresisfunction = if isReal then 'LessZC(<%e1%>, <%e2%>, data->simulationInfo->storedRelations[<%rel.index%>])' else 'Less(<%e1%>,<%e2%>)'
-          let &preExp += '<%res%> = <%hysteresisfunction%>;<%\n%>'
-          res
-        case LESSEQ(__) then
-          let hysteresisfunction = if isReal then 'LessEqZC(<%e1%>, <%e2%>, data->simulationInfo->storedRelations[<%rel.index%>])' else 'LessEq(<%e1%>,<%e2%>)'
-          let &preExp += '<%res%> = <%hysteresisfunction%>;<%\n%>'
-          res
-        case GREATER(__) then
-          let hysteresisfunction = if isReal then 'GreaterZC(<%e1%>, <%e2%>, data->simulationInfo->storedRelations[<%rel.index%>])' else 'Greater(<%e1%>,<%e2%>)'
-          let &preExp += '<%res%> = <%hysteresisfunction%>;<%\n%>'
-          res
-        case GREATEREQ(__) then
-          let hysteresisfunction = if isReal then 'GreaterEqZC(<%e1%>, <%e2%>, data->simulationInfo->storedRelations[<%rel.index%>])' else 'GreaterEq(<%e1%>,<%e2%>)'
-          let &preExp += '<%res%> = <%hysteresisfunction%>;<%\n%>'
-          res
-        end match
-    case SOME((exp,i,j)) then
-      let e1 = daeExp(rel.exp1, context, &preExp, &varDecls, &auxFunction)
-      let e2 = daeExp(rel.exp2, context, &preExp, &varDecls, &auxFunction)
-      let res = tempDecl("modelica_boolean", &varDecls)
-      if intEq(rel.index,-1) then
-        match rel.operator
-        case LESS(__) then
-          let &preExp += '<%res%> = Less(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case LESSEQ(__) then
-          let &preExp += '<%res%> = LessEq(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case GREATER(__) then
-          let &preExp += '<%res%> = Greater(<%e1%>,<%e2%>);<%\n%>'
-          res
-        case GREATEREQ(__) then
-          let &preExp += '<%res%> = GreaterEq(<%e1%>,<%e2%>);<%\n%>'
-          res
-        end match
-      else
-        let isReal = if isRealType(typeof(rel.exp1)) then (if isRealType(typeof(rel.exp2)) then 'true' else '') else ''
-        match rel.operator
-        case LESS(__) then
-          let hysteresisfunction = if isReal then 'LessZC(<%e1%>, <%e2%>, data->simulationInfo->storedRelations[<%rel.index%>])' else 'Less(<%e1%>,<%e2%>)'
-          let &preExp += '<%res%> = <%hysteresisfunction%>;<%\n%>'
-          res
-        case LESSEQ(__) then
-          let hysteresisfunction = if isReal then 'LessEqZC(<%e1%>, <%e2%>, data->simulationInfo->storedRelations[<%rel.index%>])' else 'LessEq(<%e1%>,<%e2%>)'
-          let &preExp += '<%res%> = <%hysteresisfunction%>;<%\n%>'
-          res
-        case GREATER(__) then
-          let hysteresisfunction = if isReal then 'GreaterZC(<%e1%>, <%e2%>, data->simulationInfo->storedRelations[<%rel.index%>])' else 'Greater(<%e1%>,<%e2%>)'
-          let &preExp += '<%res%> = <%hysteresisfunction%>;<%\n%>'
-          res
-        case GREATEREQ(__) then
-          let hysteresisfunction = if isReal then 'GreaterEqZC(<%e1%>, <%e2%>, data->simulationInfo->storedRelations[<%rel.index%>])' else 'GreaterEq(<%e1%>,<%e2%>)'
-          let &preExp += '<%res%> = <%hysteresisfunction%>;<%\n%>'
-          res
-        end match
-    end match
+    let e1 = daeExp(zc.exp, context, &preExp, &varDecls, &auxFunction)
+    let res = tempDecl("modelica_boolean", &varDecls)
+    let &preExp += 'RELATIONHYSTERESIS(<%res%>, <%e1%>, <%zc.index%>);<%\n%>'
+    res
   end match
 end match
-end daeExpRelationSim;
+end daeExpZeroCrossing;
 
 template daeExpIf(Exp exp, Context context, Text &preExp,
                   Text &varDecls, Text &auxFunction)
diff --git a/Compiler/Template/CodegenXML.tpl b/Compiler/Template/CodegenXML.tpl
index c109fb9391..f2d70777ac 100644
--- a/Compiler/Template/CodegenXML.tpl
+++ b/Compiler/Template/CodegenXML.tpl
@@ -2754,185 +2754,46 @@ template daeExpRelationSimXml(Exp exp, Context context, Text &preExp /*BUFP*/,
 ::=
 match exp
 case rel as RELATION(__) then
-  match context
-  case SIMULATION_CONTEXT(genDiscrete=false) then
-     match rel.optionExpisASUB
-     case NONE() then
-        let e1 = daeExpXml(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-        let e2 = daeExpXml(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-        let res = tempDeclXml("modelica_boolean", &varDecls /*BUFC*/)
-        match rel.operator
-        case LESS(__) then
-          let &preExp +=
-          <<
-          <exp:LogLt>
-            <%e1%>
-            <%e2%>
-          </exp:LogLt> <%\n%>
-          >>
-          res
-        case LESSEQ(__) then
-          let &preExp +=
-          <<
-          <exp:LogLeq>
-            <%e1%>
-            <%e2%>
-          </exp:LogLeq> <%\n%>
-          >>
-          res
-        case GREATER(__) then
-          let &preExp +=
-          <<
-          <exp:LogGt>
-            <%e1%>
-            <%e2%>
-          </exp:LogGt> <%\n%>
-          >>
-          res
-        case GREATEREQ(__) then
-          let &preExp +=
-          <<
-          <exp:LogGeq>
-            <%e1%>
-            <%e2%>
-          </exp:LogGeq> <%\n%>
-          >>
-          res
-        end match
-    case SOME((exp,i,j)) then
-      let e1 = daeExpXml(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-      let e2 = daeExpXml(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-      let iterator = daeExpXml(exp, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-      let res = tempDeclXml("modelica_boolean", &varDecls /*BUFC*/)
-      //let e3 = daeExp(createArray(i), context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-      match rel.operator
-      case LESS(__) then
-        let &preExp +=
-        <<
-          <exp:LogLt>
-            <%e1%>
-            <%e2%>
-          </exp:LogLt><%\n%>
-        >>
-        res
-      case LESSEQ(__) then
-        let &preExp +=
-        <<
-          <exp:LogLeq>
-            <%e1%>
-            <%e2%>
-          <exp:LogLeq> <%\n%>
-        >>
-        res
-      case GREATER(__) then
-        let &preExp +=
-        <<
-          <exp:LogGt>
-            <%e1%>
-            <%e2%>
-          </exp:LogGt><%\n%>
-        >>
-        res
-      case GREATEREQ(__) then
-        let &preExp +=
-        <<
-          <exp:LogGeq>
-            <%e1%>
-            <%e2%>
-          </exp:LogGeq><%\n%>
-        >>
-        res
-        end match
-      end match
-   case SIMULATION_CONTEXT(genDiscrete=true) then
-     match rel.optionExpisASUB
-     case NONE() then
-        let e1 = daeExpXml(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-        let e2 = daeExpXml(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-        let res = tempDeclXml("modelica_boolean", &varDecls /*BUFC*/)
-       match rel.operator
-        case LESS(__) then
-          let &preExp +=
-          <<
-          <exp:LogLt>
-            <%e1%>
-            <%e2%>
-          </exp:LogLt><%\n%>
-          >>
-          res
-        case LESSEQ(__) then
-          let &preExp +=
-          <<
-          <exp:LogLeq>
-            <%e1%>
-            <%e2%>
-          </exp:LogLeq> <%\n%>
-          >>
-          res
-        case GREATER(__) then
-          let &preExp +=
-          <<
-          <exp:LogGt>
-            <%e1%>
-            <%e2%>
-          </exp:LogGt><%\n%>
-          >>
-          res
-        case GREATEREQ(__) then
-          let &preExp +=
-          <<
-          <exp:LogGeq>
-            <%e1%>
-            <%e2%>
-          </exp:LogGeq><%\n%>
-          >>
-          res
-        end match
-    case SOME((exp,i,j)) then
-         let e1 = daeExpXml(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-         let e2 = daeExpXml(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-         let res = tempDeclXml("modelica_boolean", &varDecls /*BUFC*/)
-         //let e3 = daeExp(createArray(i), context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-         let iterator = daeExpXml(exp, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-     match rel.operator
-     case LESS(__) then
-        let &preExp +=
-        <<
-            <exp:LogLt>
-              <%e1%>
-              <%e2%>
-            </exp:LogLt><%\n%>
-        >>
-        res
-     case LESSEQ(__) then
-        let &preExp +=
-        <<
-            <exp:LogLeq>
-              <%e1%>
-              <%e2%>
-            </exp:LogLeq> <%\n%>
-        >>
-        res
-     case GREATER(__) then
-        let &preExp +=
-        <<
-            <exp:LogGt>
-              <%e1%>
-              <%e2%>
-            </exp:LogGt><%\n%>
-        >>
-        res
-     case GREATEREQ(__) then
-        let &preExp +=
-        <<
-            <exp:LogGeq>
-              <%e1%>
-              <%e2%>
-            </exp:LogGeq><%\n%>
-        >>
-        res
-          end match
-        end match
+  let e1 = daeExpXml(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
+  let e2 = daeExpXml(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
+  let res = tempDeclXml("modelica_boolean", &varDecls /*BUFC*/)
+  match rel.operator
+  case LESS(__) then
+    let &preExp +=
+    <<
+    <exp:LogLt>
+      <%e1%>
+      <%e2%>
+    </exp:LogLt> <%\n%>
+    >>
+    res
+  case LESSEQ(__) then
+    let &preExp +=
+    <<
+    <exp:LogLeq>
+      <%e1%>
+      <%e2%>
+    </exp:LogLeq> <%\n%>
+    >>
+    res
+  case GREATER(__) then
+    let &preExp +=
+    <<
+    <exp:LogGt>
+      <%e1%>
+      <%e2%>
+    </exp:LogGt> <%\n%>
+    >>
+    res
+  case GREATEREQ(__) then
+    let &preExp +=
+    <<
+    <exp:LogGeq>
+      <%e1%>
+      <%e2%>
+    </exp:LogGeq> <%\n%>
+    >>
+    res
   end match
 end match
 end daeExpRelationSimXml;
@@ -2945,12 +2806,10 @@ match exp
 case rel as RELATION(__) then
   match context
    case SIMULATION_CONTEXT(genDiscrete=true) then
-     match rel.optionExpisASUB
-     case NONE() then
-        let e1 = daeExpXml(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-        let e2 = daeExpXml(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
-        let res = tempDeclXml("modelica_boolean", &varDecls /*BUFC*/)
-       match rel.operator
+      let e1 = daeExpXml(rel.exp1, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
+      let e2 = daeExpXml(rel.exp2, context, &preExp /*BUFC*/, &varDecls /*BUFC*/)
+      let res = tempDeclXml("modelica_boolean", &varDecls /*BUFC*/)
+      match rel.operator
         case EQUAL(__) then
           <<
           <opt:ConstraintEqu>
@@ -2976,8 +2835,7 @@ case rel as RELATION(__) then
           <<
             "The XML schema does only support =, >= , <=  operators for constraints"
           >>
-        end match
-        end match
+      end match
   end match
 end match
 end daeExpConstraintXml;
diff --git a/Compiler/Template/DAEDumpTV.mo b/Compiler/Template/DAEDumpTV.mo
index dce9c235ae..1bf96739e7 100644
--- a/Compiler/Template/DAEDumpTV.mo
+++ b/Compiler/Template/DAEDumpTV.mo
@@ -1223,17 +1223,17 @@ package DAE
       Exp exp;
     end LUNARY;
 
-    record RELATION "Relation, e.g. a <= 0
-      Index contains normal an Integer for every ZeroCrossing
-      but if Relation is in algorithm with for loop the iterator and the range
-      of static iterator is needed for codegen"
+    record RELATION "Relation, e.g. a <= 0"
       Exp exp1;
       Operator operator;
       Exp exp2;
-      Integer index;
-      Option<tuple<Exp,Integer,Integer>> optionExpisASUB;
     end RELATION;
 
+    record ZEROCROSSING "Backend expression for zero crossing"
+      Exp exp;
+      Integer index;
+    end ZEROCROSSING;
+
     record IFEXP "If expressions"
       Exp expCond;
       Exp expThen;
diff --git a/Compiler/Template/SimCodeTV.mo b/Compiler/Template/SimCodeTV.mo
index 7774a2f03f..caea924d03 100644
--- a/Compiler/Template/SimCodeTV.mo
+++ b/Compiler/Template/SimCodeTV.mo
@@ -1598,9 +1598,11 @@ package DAE
       Exp exp1;
       Operator operator;
       Exp exp2;
-      Integer index;
-      Option<tuple<DAE.Exp,Integer,Integer>> optionExpisASUB;
     end RELATION;
+    record ZEROCROSSING "Backend expression for zero crossing"
+      Exp exp;
+      Integer index;
+    end ZEROCROSSING;
     record IFEXP
       Exp expCond;
       Exp expThen;