diff --git a/AlgebraicDataflowArchitectureModel/src/algorithm/DataStorageNecessity.java b/AlgebraicDataflowArchitectureModel/src/algorithm/DataStorageNecessity.java
index 0625664..c9aac3e 100644
--- a/AlgebraicDataflowArchitectureModel/src/algorithm/DataStorageNecessity.java
+++ b/AlgebraicDataflowArchitectureModel/src/algorithm/DataStorageNecessity.java
@@ -16,7 +16,7 @@
 				boolean flag = false;
 				for (Position pos : curexp.getVariables().keySet()) {
 					System.out.println(curexp);
-					System.out.println(nextexp.getVariables().containsKey(pos));
+					System.out.println(curexp.getVariables().containsKey(pos));
 					System.out.println(nextexp);
 					if (nextexp.contains(curexp.getVariables().get(pos))) {
 						flag = true;
diff --git a/AlgebraicDataflowArchitectureModel/src/models/algebra/Position.java b/AlgebraicDataflowArchitectureModel/src/models/algebra/Position.java
index 1708506..d157bee 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/algebra/Position.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/algebra/Position.java
@@ -3,6 +3,8 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import models.dataConstraintModel.IdentifierTemplate;
+
 public class Position implements Cloneable {
 	private ArrayList<Integer> orders = new ArrayList<Integer>();
 	
@@ -32,4 +34,13 @@
 	public Object clone() {
 		return new Position((ArrayList<Integer>) orders.clone());
 	}
+	
+	public boolean equals(Object another) {
+		if (!(another instanceof Position)) return false;
+		return orders.equals(((Position) another).orders);
+	}
+	
+	public int hashCode() {
+		return orders.size();
+	}
 }
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/IdentifierTemplate.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/IdentifierTemplate.java
index 0ea7b6a..d16617b 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/IdentifierTemplate.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/IdentifierTemplate.java
@@ -33,4 +33,13 @@
 	public void setResourceStateType(Type resourceStateType) {
 		this.resourceStateType = resourceStateType;
 	}
+	
+	public boolean equals(Object another) {
+		if (!(another instanceof IdentifierTemplate)) return false;
+		return resourceName.equals(((IdentifierTemplate) another).resourceName);
+	}
+	
+	public int hashCode() {
+		return resourceName.hashCode();
+	}
 }
diff --git a/AlgebraicDataflowArchitectureModel/src/tests/DerivingStorageResourcesTest.java b/AlgebraicDataflowArchitectureModel/src/tests/DerivingStorageResourcesTest.java
index ae31879..d964d85 100644
--- a/AlgebraicDataflowArchitectureModel/src/tests/DerivingStorageResourcesTest.java
+++ b/AlgebraicDataflowArchitectureModel/src/tests/DerivingStorageResourcesTest.java
@@ -46,7 +46,9 @@
 				ResourceDependencyGraph graph = DataStorageNecessity.run(model);
 				for (Node n:graph.getNodes()) {
 					ResourceNode resource = (ResourceNode)n;
-					System.out.println(((StoreAttribute)resource.getAttribute()).isStored());
+					if((StoreAttribute)resource.getAttribute() != null) {
+						System.out.println(resource.toString() + ":"  + ((StoreAttribute)resource.getAttribute()).isNeeded());
+					}
 				}
 			} catch (ExpectedChannel | ExpectedChannelName | ExpectedLeftCurlyBracket | ExpectedInOrOutKeyword
 					| ExpectedStateTransition | ExpectedEquals | ExpectedRHSExpression | WrongLHSExpression