diff --git a/AlgebraicDataflowArchitectureModel/models/GroupChat.model b/AlgebraicDataflowArchitectureModel/models/GroupChat.model
index d8b0c42..f199175 100644
--- a/AlgebraicDataflowArchitectureModel/models/GroupChat.model
+++ b/AlgebraicDataflowArchitectureModel/models/GroupChat.model
@@ -19,9 +19,9 @@
 }
 
 channel Notify(gid:Str) {
-	in groups.{gid}.messages(prevMesList, notify(id)) = mesList
+	in groups.{gid}.messages(prevMesList, notify(m)) = mesList
 	for EachMember(mno:Int) {
-		ref groups.{gid}.members.{mno}(id:Str, notify(id))
-		out accounts.{id}.notifications(prevNtMap:Map, notify(id)) = insert(prevNtMap, gid, true)
+		ref groups.{gid}.members.{mno}(m.{mno}:Str, notify(m))
+		out accounts.{m.{mno}}.notifications(prevNtMap:Map, notify(m)) = insert(prevNtMap, gid, true)
 	}
 }
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/DataConstraintModel.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/DataConstraintModel.java
index e44c50c..858ecb4 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/DataConstraintModel.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/DataConstraintModel.java
@@ -962,7 +962,7 @@
 		lookup.setSignature(new Type[] {null, typeMap, null});
 		addMember.setSignature(new Type[] {typeJson, typeJson, typeString, null});
 		dot.setSignature(new Type[] {null, typeJson, typeString});
-		dotParam.setSignature(new Type[] {null, null, null});
+		dotParam.setSignature(new Type[] {null, typeJson, null});
 		pi.setSignature(new Type[] {typeDouble});
 		E.setSignature(new Type[] {typeDouble});
 		sqrt.setSignature(new Type[] {typeDouble, typeDouble});
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/JsonAccessor.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/JsonAccessor.java
index 26a4069..b6c4ad3 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/JsonAccessor.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/JsonAccessor.java
@@ -38,7 +38,7 @@
 	public Expression reduce() {
 		Expression reducedTerm = super.reduce();
 		if (reducedTerm instanceof Term) {
-			if (symbol.equals(DataConstraintModel.dot) && getChildren().size() >= 2) {
+			if ((symbol == DataConstraintModel.dot || symbol == DataConstraintModel.dotParam) && getChildren().size() >= 2) {
 				// this term is `json.key`.
 				Expression expJson = getChild(0);
 				Expression expKey = getChild(1);
@@ -54,18 +54,21 @@
 		if (json instanceof JsonTerm) {
 			return ((JsonTerm) json).get(key);
 		}
-		if (!json.getSymbol().equals(DataConstraintModel.addMember)) {
-			return new Constant(DataConstraintModel.null_);
-		}
-		if (json.getChild(1).equals(key)) {
-			Expression value = json.getChild(2);
-			if (value == null) {
-				return new Constant(DataConstraintModel.null_);
+		if (json.getSymbol().equals(DataConstraintModel.addMember) || json.getSymbol().equals(DataConstraintModel.set)) {
+			if (json.getChild(1).equals(key)) {
+				Expression value = json.getChild(2);
+				if (value == null) {
+					return new Constant(DataConstraintModel.null_);
+				}
+				return value;
 			}
-			return value;
+			if (json.getChild(0) == null 
+					|| (json.getChild(0) instanceof Term && 
+							(((Term) json.getChild(0)).getSymbol().equals(DataConstraintModel.null_)) 
+							|| ((Term) json.getChild(0)).getSymbol().equals(DataConstraintModel.nil))) return null;
+			return getValue((Term) json.getChild(0), key);
 		}
-		if (json.getChild(0) == null || (json.getChild(0) instanceof Term && ((Term) json.getChild(0)).getSymbol().equals(DataConstraintModel.null_))) return null;
-		return getValue((Term) json.getChild(0), key);
+		return new Constant(DataConstraintModel.null_);
 	}
 
 	@Override
@@ -75,7 +78,7 @@
 		int i = targetPos.removeHeadOrder();
 		Symbol[] inverseSymbols = symbol.getInverses();
 		if (i == 0) {
-			if (symbol.equals(DataConstraintModel.dot) && getChildren().size() >= 2) {
+			if (symbol == DataConstraintModel.dot && getChildren().size() >= 2) {
 				// this term is `json.key`.
 				Expression expJson = getChild(0);
 				Expression expKey = getChild(1);
@@ -112,7 +115,7 @@
 					LambdaAbstraction lambdaAbstraction = new LambdaAbstraction(var, jsonTerm);	// v -> addMember(jsonTerm, key, v)
 					inverseSymbols = new Symbol[] { lambdaAbstraction };
 				}
-			} else if (symbol.equals(DataConstraintModel.dotParam) && getChildren().size() >= 2) {
+			} else if (symbol == DataConstraintModel.dotParam && getChildren().size() >= 2) {
 				// this term is `json.{param}`.
 				Expression expListOrMap = getChild(0);
 				Expression expKey = getChild(1);
@@ -124,9 +127,9 @@
 				}
 				Type keyType = null;
 				if (expKey instanceof Variable) {
-					keyType = (JsonType) ((Variable) expKey).getType();
+					keyType = ((Variable) expKey).getType();
 				} else if (expKey instanceof Term) {
-					keyType = (JsonType) ((Term) expKey).getType();
+					keyType = ((Term) expKey).getType();
 				}
 				if (jsonType != null && keyType != null) { 
 					if (DataConstraintModel.typeList.isAncestorOf(jsonType) || keyType.equals(DataConstraintModel.typeInt)) {
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java b/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
index 5e408c5..9466c25 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
@@ -22,6 +22,7 @@
 import models.dataConstraintModel.ChannelMember;
 import models.dataConstraintModel.ResourcePath;
 import models.dataConstraintModel.Selector;
+import parser.Parser;
 
 public class DataTransferChannel extends Channel {
 	protected Set<ChannelMember> inputChannelMembers = null;
@@ -620,12 +621,12 @@
 	public String toString() {
 		String channelSource = "";
 		if (isNative()) {
-			channelSource += "native ";
+			channelSource += Parser.NATIVE + " ";
 		}
 		if (parent == null) {
-			channelSource += "channel " + getChannelName();
+			channelSource += Parser.CHANNEL + " " + getChannelName();
 		} else {
-			channelSource += "sub " + getChannelName();
+			channelSource += Parser.SUB_CHANNEL + " " + getChannelName();
 		}
 		if (getSelectors().size() > 0) {
 			channelSource += "(";
@@ -638,13 +639,13 @@
 		}
 		channelSource += " {\n";
 		for (ChannelMember inputMember: inputChannelMembers) {
-			channelSource += "\t in " + inputMember + "\n";
+			channelSource += "\t " + Parser.IN + " " + inputMember + "\n";
 		}
 		for (ChannelMember refMember: referenceChannelMembers) {
-			channelSource += "\t ref " + refMember + "\n";
+			channelSource += "\t " + Parser.REF + " " + refMember + "\n";
 		}
 		for (ChannelMember outputMember: outputChannelMembers) {
-			channelSource += "\t out " + outputMember + "\n";
+			channelSource += "\t " + Parser.OUT + " " + outputMember + "\n";
 		}
 		for (Channel childCh: getChildren()) {
 			channelSource += childCh.toString();
diff --git a/AlgebraicDataflowArchitectureModel/src/simulator/Event.java b/AlgebraicDataflowArchitectureModel/src/simulator/Event.java
index a1f0302..23dfafa 100644
--- a/AlgebraicDataflowArchitectureModel/src/simulator/Event.java
+++ b/AlgebraicDataflowArchitectureModel/src/simulator/Event.java
@@ -14,6 +14,7 @@
 import models.algebra.Position;
 import models.algebra.Term;
 import models.algebra.UnificationFailed;
+import models.algebra.Variable;
 import models.dataConstraintModel.Channel;
 import models.dataConstraintModel.ChannelMember;
 import models.dataConstraintModel.ResourcePath;
@@ -39,8 +40,8 @@
 	private Map<Expression, Expression> dependingParameters = new HashMap<>();
 	private Set<Resource> outputResources = new HashSet<>();
 	private Set<Event> childEvents = new HashSet<>();
-	private Map<Selector, Map<ResourcePath, Integer>> channelSelectorToInputOrReferenceResourcePathParam = new HashMap<>();
-	private Map<Selector, Map<ResourcePath, Integer>> channelSelectorToOutputResourcePathParam = new HashMap<>();
+	private Map<Selector, Map<ResourcePath, Map.Entry<Integer, Set<Position>>>> channelSelectorToInputOrReferenceResourcePathParam = new HashMap<>();
+	private Map<Selector, Map<ResourcePath, Map.Entry<Integer, Set<Position>>>> channelSelectorToOutputResourcePathParam = new HashMap<>();
 	
 	/**
 	 * Constructor for an input event channel
@@ -60,13 +61,13 @@
 		// Extract the values of the channel selectors from the output resource.
 		List<Selector> channelSelectors = channel.getAllSelectors();
 		for (Selector sel: channelSelectors) {
-			int paramIdx = channelSelectorToOutputResourcePathParam.get(sel).get(outputResPath);
+			Map.Entry<Integer, Set<Position>> paramIdxAndPos = channelSelectorToOutputResourcePathParam.get(sel).get(outputResPath);
 			Resource ancestor = outputResource;
 			int idx = outputResPath.getPathParams().size();
 			while (ancestor != null) {
 				if (ancestor.getResourceHierarchy().getNumParameters() > 0) {
 					idx--;
-					if (idx == paramIdx) break;
+					if (idx == paramIdxAndPos.getKey()) break;
 				}
 				ancestor = ancestor.getParent();
 			}
@@ -92,14 +93,14 @@
 		List<Selector> channelSelectors = channel.getAllSelectors();
 		for (Selector sel: channelSelectors) {
 			if (inputResPath != null) {
-				Integer paramIdx = channelSelectorToInputOrReferenceResourcePathParam.get(sel).get(inputResPath);
-				if (paramIdx != null) {
+				Map.Entry<Integer, Set<Position>> paramIdxAndPos = channelSelectorToInputOrReferenceResourcePathParam.get(sel).get(inputResPath);
+				if (paramIdxAndPos != null) {
 					Resource ancestor = inputResource;
 					int idx = inputResPath.getPathParams().size();
 					while (ancestor != null) {
 						if (ancestor.getResourceHierarchy().getNumParameters() > 0) {
 							idx--;
-							if (idx == paramIdx) break;
+							if (idx == paramIdxAndPos.getKey()) break;
 						}
 						ancestor = ancestor.getParent();
 					}
@@ -137,37 +138,54 @@
 	private void connectChannelSelectorAndPathParameters() {
 		List<Selector> channelSelectors = channel.getAllSelectors();
 		for (Selector sel: channelSelectors) {
-			for (ResourcePath resPath: channel.getInputResources()) {
-				int paramIdx = resPath.getPathParams().indexOf(sel.getExpression());
-				if (paramIdx >= 0) {
-					Map<ResourcePath, Integer> pathToIdx = channelSelectorToInputOrReferenceResourcePathParam.get(sel);
-					if (pathToIdx == null) {
-						pathToIdx = new HashMap<>();
-						channelSelectorToInputOrReferenceResourcePathParam.put(sel, pathToIdx);
+			Set<ResourcePath> inputAndReferenceResPaths = new HashSet<>(channel.getInputResources());
+			inputAndReferenceResPaths.addAll(channel.getReferenceResources());
+			for (ResourcePath resPath: inputAndReferenceResPaths) {
+				for (int paramIdx = 0; paramIdx < resPath.getPathParams().size(); paramIdx++) {
+					Expression pathParam = resPath.getPathParams().get(paramIdx);
+					if (pathParam.contains(sel.getExpression())) {
+						for (Map.Entry<Position, Variable> posAndVar:  pathParam.getVariables().entrySet()) {
+							Position p = posAndVar.getKey();
+							Variable v = posAndVar.getValue();
+							if (v.equals(sel.getExpression())) {
+								Map<ResourcePath, Map.Entry<Integer, Set<Position>>> pathToIdxAndPos = channelSelectorToInputOrReferenceResourcePathParam.get(sel);
+								if (pathToIdxAndPos == null) {
+									pathToIdxAndPos = new HashMap<>();
+									channelSelectorToInputOrReferenceResourcePathParam.put(sel, pathToIdxAndPos);
+								}
+								Map.Entry<Integer, Set<Position>> idxAndPos = pathToIdxAndPos.get(resPath);
+								if (idxAndPos == null) {
+									idxAndPos = new AbstractMap.SimpleEntry<>(paramIdx, new HashSet<>());
+									pathToIdxAndPos.put(resPath, idxAndPos);
+								}
+								idxAndPos.getValue().add(p);
+							}
+						}
 					}
-					pathToIdx.put(resPath, paramIdx);
-				}
-			}
-			for (ResourcePath resPath: channel.getReferenceResources()) {
-				int paramIdx = resPath.getPathParams().indexOf(sel.getExpression());
-				if (paramIdx >= 0) {
-					Map<ResourcePath, Integer> pathToIdx = channelSelectorToInputOrReferenceResourcePathParam.get(sel);
-					if (pathToIdx == null) {
-						pathToIdx = new HashMap<>();
-						channelSelectorToInputOrReferenceResourcePathParam.put(sel, pathToIdx);
-					}
-					pathToIdx.put(resPath, paramIdx);
 				}
 			}
 			for (ResourcePath resPath: channel.getOutputResources()) {
-				int paramIdx = resPath.getPathParams().indexOf(sel.getExpression());
-				if (paramIdx >= 0) {
-					Map<ResourcePath, Integer> pathToIdx = channelSelectorToOutputResourcePathParam.get(sel);
-					if (pathToIdx == null) {
-						pathToIdx = new HashMap<>();
-						channelSelectorToOutputResourcePathParam.put(sel, pathToIdx);
+				for (int paramIdx = 0; paramIdx < resPath.getPathParams().size(); paramIdx++) {
+					Expression pathParam = resPath.getPathParams().get(paramIdx);
+					if (pathParam.contains(sel.getExpression())) {
+						for (Map.Entry<Position, Variable> posAndVar:  pathParam.getVariables().entrySet()) {
+							Position p = posAndVar.getKey();
+							Variable v = posAndVar.getValue();
+							if (v.equals(sel.getExpression())) {
+								Map<ResourcePath, Map.Entry<Integer, Set<Position>>> pathToIdxAndPos = channelSelectorToOutputResourcePathParam.get(sel);
+								if (pathToIdxAndPos == null) {
+									pathToIdxAndPos = new HashMap<>();
+									channelSelectorToOutputResourcePathParam.put(sel, pathToIdxAndPos);
+								}
+								Map.Entry<Integer, Set<Position>> idxAndPos = pathToIdxAndPos.get(resPath);
+								if (idxAndPos == null) {
+									idxAndPos = new AbstractMap.SimpleEntry<>(paramIdx, new HashSet<>());
+									pathToIdxAndPos.put(resPath, idxAndPos);
+								}
+								idxAndPos.getValue().add(p);
+							}
+						}
 					}
-					pathToIdx.put(resPath, paramIdx);
 				}
 			}
 		}
@@ -488,21 +506,33 @@
 		ResourceIdentifier resId = ResourceIdentifier.createFrom(resPath);
 		for (Map.Entry<Selector, Constant> chParamEnt: channelSelectorAndValues) {
 			Selector sel = chParamEnt.getKey();
-			Map<ResourcePath, Integer> inputPathParamEnt = channelSelectorToInputOrReferenceResourcePathParam.get(sel);
-			if (inputPathParamEnt != null) {
-				Integer paramIdx = inputPathParamEnt.get(resPath);
-				if (paramIdx != null) {
-					resId.setPathParam(paramIdx, chParamEnt.getValue());
+			Map<ResourcePath, Map.Entry<Integer, Set<Position>>> inputPathToIdxAndPos = channelSelectorToInputOrReferenceResourcePathParam.get(sel);
+			if (inputPathToIdxAndPos != null) {
+				Map.Entry<Integer, Set<Position>> pathParamEnt = inputPathToIdxAndPos.get(resPath);
+				if (pathParamEnt != null) {
+					Integer paramIdx = pathParamEnt.getKey();
+					if (paramIdx != null) {
+						Expression pathParamExp = resId.getPathParams().get(paramIdx);
+						if (pathParamExp instanceof Variable) {
+							resId.setPathParam(paramIdx, chParamEnt.getValue());
+						}
+					}
 				}
 			}
 		}
 		for (Map.Entry<Selector, Constant> chParamEnt: channelSelectorAndValues) {
 			Selector sel = chParamEnt.getKey();
-			Map<ResourcePath, Integer> outputPathParamEnt = channelSelectorToOutputResourcePathParam.get(sel);
-			if (outputPathParamEnt != null) {
-				Integer paramIdx = outputPathParamEnt.get(resPath);
-				if (paramIdx != null) {
-					resId.setPathParam(paramIdx, chParamEnt.getValue());
+			Map<ResourcePath, Map.Entry<Integer, Set<Position>>> outputPathToIdxAndPos = channelSelectorToOutputResourcePathParam.get(sel);
+			if (outputPathToIdxAndPos != null) {
+				Map.Entry<Integer, Set<Position>> pathParamEnt = outputPathToIdxAndPos.get(resPath);
+				if (pathParamEnt != null) {
+					Integer paramIdx = pathParamEnt.getKey();
+					if (paramIdx != null) {
+						Expression pathParamExp = resId.getPathParams().get(paramIdx);
+						if (pathParamExp instanceof Variable) {
+							resId.setPathParam(paramIdx, chParamEnt.getValue());
+						}
+					}
 				}
 			}
 		}
@@ -512,6 +542,40 @@
 				resId.setPathParam(paramIdx, (Constant) dependingParameters.get(var));
 			}
 		}
+		for (Map.Entry<Selector, Constant> chParamEnt: channelSelectorAndValues) {
+			Selector sel = chParamEnt.getKey();
+			Map<ResourcePath, Map.Entry<Integer, Set<Position>>> inputPathToIdxAndPos = channelSelectorToInputOrReferenceResourcePathParam.get(sel);
+			if (inputPathToIdxAndPos != null) {
+				Map.Entry<Integer, Set<Position>> pathParamEnt = inputPathToIdxAndPos.get(resPath);
+				if (pathParamEnt != null) {
+					Integer paramIdx = pathParamEnt.getKey();
+					if (paramIdx != null) {
+						Expression pathParamExp = resId.getPathParams().get(paramIdx);
+						if (pathParamExp instanceof Term && sel.getExpression() instanceof Variable) {
+							pathParamExp = ((Term) pathParamExp).substitute((Variable) sel.getExpression(), chParamEnt.getValue());
+							resId.setPathParam(paramIdx, ((Term) pathParamExp).reduce());
+						}
+					}
+				}
+			}
+		}
+		for (Map.Entry<Selector, Constant> chParamEnt: channelSelectorAndValues) {
+			Selector sel = chParamEnt.getKey();
+			Map<ResourcePath, Map.Entry<Integer, Set<Position>>> outputPathToIdxAndPos = channelSelectorToOutputResourcePathParam.get(sel);
+			if (outputPathToIdxAndPos != null) {
+				Map.Entry<Integer, Set<Position>> pathParamEnt = outputPathToIdxAndPos.get(resPath);
+				if (pathParamEnt != null) {
+				Integer paramIdx = pathParamEnt.getKey();
+					if (paramIdx != null) {
+						Expression pathParamExp = resId.getPathParams().get(paramIdx);
+						if (pathParamExp instanceof Term && sel.getExpression() instanceof Variable) {
+							pathParamExp = ((Term) pathParamExp).substitute((Variable) sel.getExpression(), chParamEnt.getValue());
+							resId.setPathParam(paramIdx, ((Term) pathParamExp).reduce());
+						}
+					}
+				}
+			}
+		}
 		return resId;
 	}
 	
@@ -520,9 +584,15 @@
 		for (Map.Entry<Selector, Constant> chParamEnt: channelSelectorAndValues) {
 			Selector sel = chParamEnt.getKey();
 			if (channelSelectorToInputOrReferenceResourcePathParam.get(sel) != null) {
-				Integer paramIdx = channelSelectorToInputOrReferenceResourcePathParam.get(sel).get(inputResPath);
-				if (paramIdx != null) {
-					resId.setPathParam(paramIdx, chParamEnt.getValue());
+				Map.Entry<Integer, Set<Position>> pathParamEnt = channelSelectorToInputOrReferenceResourcePathParam.get(sel).get(inputResPath);
+				if (pathParamEnt != null) {
+					Integer paramIdx = pathParamEnt.getKey();
+					if (paramIdx != null) {
+						Expression pathParamExp = resId.getPathParams().get(paramIdx);
+						if (pathParamExp instanceof Variable) {
+							resId.setPathParam(paramIdx, chParamEnt.getValue());
+						}
+					}
 				}
 			}
 		}
@@ -532,6 +602,22 @@
 				resId.setPathParam(paramIdx, (Constant) dependingParameters.get(var));
 			}
 		}
+		for (Map.Entry<Selector, Constant> chParamEnt: channelSelectorAndValues) {
+			Selector sel = chParamEnt.getKey();
+			if (channelSelectorToInputOrReferenceResourcePathParam.get(sel) != null) {
+				Map.Entry<Integer, Set<Position>> pathParamEnt = channelSelectorToInputOrReferenceResourcePathParam.get(sel).get(inputResPath);
+				if (pathParamEnt != null) {
+					Integer paramIdx = pathParamEnt.getKey();
+					if (paramIdx != null) {
+						Expression pathParamExp = resId.getPathParams().get(paramIdx);
+						if (pathParamExp instanceof Term && sel.getExpression() instanceof Variable) {
+							pathParamExp = ((Term) pathParamExp).substitute((Variable) sel.getExpression(), chParamEnt.getValue());
+							resId.setPathParam(paramIdx, ((Term) pathParamExp).reduce());
+						}
+					}
+				}
+			}
+		}
 		return resId;
 	}
 
@@ -540,16 +626,38 @@
 		for (Map.Entry<Selector, Constant> chParamEnt: channelSelectorAndValues) {
 			Selector sel = chParamEnt.getKey();
 			if (channelSelectorToOutputResourcePathParam.get(sel) != null) {
-				Integer paramIdx = channelSelectorToOutputResourcePathParam.get(sel).get(outputResPath);
-				if (paramIdx != null) {
-					resId.setPathParam(paramIdx, chParamEnt.getValue());
+				Map.Entry<Integer, Set<Position>> pathParamEnt = channelSelectorToOutputResourcePathParam.get(sel).get(outputResPath);
+				if (pathParamEnt != null) {
+					Integer paramIdx = pathParamEnt.getKey();
+					if (paramIdx != null) {
+						Expression pathParamExp = resId.getPathParams().get(paramIdx);
+						if (pathParamExp instanceof Variable) {
+							resId.setPathParam(paramIdx, chParamEnt.getValue());
+						}
+					}
 				}
 			}
 		}
 		for (Expression var: dependingParameters.keySet()) {
 			int paramIdx = resId.getPathParams().indexOf(var);
 			if (paramIdx >= 0) {
-				resId.setPathParam(paramIdx, (Constant) dependingParameters.get(var));
+				resId.setPathParam(paramIdx, dependingParameters.get(var));
+			}
+		}
+		for (Map.Entry<Selector, Constant> chParamEnt: channelSelectorAndValues) {
+			Selector sel = chParamEnt.getKey();
+			if (channelSelectorToOutputResourcePathParam.get(sel) != null) {
+				Map.Entry<Integer, Set<Position>> pathParamEnt = channelSelectorToOutputResourcePathParam.get(sel).get(outputResPath);
+				if (pathParamEnt != null) {
+					Integer paramIdx = pathParamEnt.getKey();
+					if (paramIdx != null) {
+						Expression pathParamExp = resId.getPathParams().get(paramIdx);
+						if (pathParamExp instanceof Term && sel.getExpression() instanceof Variable) {
+							pathParamExp = ((Term) pathParamExp).substitute((Variable) sel.getExpression(), chParamEnt.getValue());
+							resId.setPathParam(paramIdx, ((Term) pathParamExp).reduce());
+						}
+					}
+				}
 			}
 		}
 		return resId;
diff --git a/AlgebraicDataflowArchitectureModel/src/simulator/ResourceIdentifier.java b/AlgebraicDataflowArchitectureModel/src/simulator/ResourceIdentifier.java
index 8987ee0..13b2c92 100644
--- a/AlgebraicDataflowArchitectureModel/src/simulator/ResourceIdentifier.java
+++ b/AlgebraicDataflowArchitectureModel/src/simulator/ResourceIdentifier.java
@@ -25,7 +25,7 @@
 		super(parentResId, exp, resourceHierarchy);
 	}
 
-	public void setPathParam(int paramIdx, Constant param) {
+	public void setPathParam(int paramIdx, Expression param) {
 		if (paramIdx < pathParams.size()) {
 			pathParams.set(paramIdx, new AbstractMap.SimpleEntry<>(param, null));
 			if (parent != null) {
@@ -130,7 +130,7 @@
 				return new ResourceIdentifier(parent, resPath.getLeafResourceName(), res);
 			}
 		} else {
-			return new ResourceIdentifier(parent, resPath.getLastParam(), res);
+			return new ResourceIdentifier(parent, (Expression) resPath.getLastParam().clone(), res);
 		}
 	}