diff --git a/src/de/dhbwstuttgart/typeinference/unify/RuleSet.java b/src/de/dhbwstuttgart/typeinference/unify/RuleSet.java
index 9ce84a43..e18e6156 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/RuleSet.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/RuleSet.java
@@ -376,8 +376,8 @@ public class RuleSet implements IRuleSet{
 		if(!(typeDs instanceof ReferenceType))
 			return Optional.empty();
 		
-		if(typeD.getTypeParams().size() == 0 || typeDs.getTypeParams().size() == 0)
-			return Optional.empty();
+		/*if(typeD.getTypeParams().size() == 0 || typeDs.getTypeParams().size() == 0)
+			return Optional.empty();*/
 		
 		if(typeD.getName().equals(typeDs.getName()))
 			return Optional.empty();
@@ -402,8 +402,8 @@ public class RuleSet implements IRuleSet{
 		TypeParams typeDParams = typeD.getTypeParams();
 		TypeParams typeDgenParams = typeDgen.getTypeParams();
 		
-		Unifier unif = new Unifier((PlaceholderType) typeDgenParams.get(0), typeDParams.get(0));
-		for(int i = 1; i < typeDParams.size(); i++) 
+		Unifier unif = Unifier.Identity();
+		for(int i = 0; i < typeDParams.size(); i++) 
 			unif.Add((PlaceholderType) typeDgenParams.get(i), typeDParams.get(i));
 		
 		return Optional.of(new UnifyPair(unif.apply(newLhs), typeDs, PairOperator.SMALLERDOT));
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/FunNType.java b/src/de/dhbwstuttgart/typeinference/unify/model/FunNType.java
index e62fd6ce..cb431cf9 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/FunNType.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/FunNType.java
@@ -6,17 +6,28 @@ import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
 
 public class FunNType extends UnifyType {
 
-	public FunNType(TypeParams p) {
+	protected FunNType(TypeParams p) {
 		super("FuN", p);
-		if(p.size() == 0)
-			throw new IllegalArgumentException("Function types need at least one type parameter");
 	}
 
+	public static FunNType getFunNType(TypeParams tp) {
+		if(!validateTypeParams(tp))
+			throw new IllegalArgumentException("Invalid TypeParams for a FunNType: " + tp);
+		return new FunNType(tp);
+	}
+	
+	private static boolean validateTypeParams(TypeParams tp) {
+		if(tp.size() == 0)
+			return false;
+		for(UnifyType t : tp)
+			if(t instanceof WildcardType)
+				return false;
+		return true;
+	}
+	
 	@Override
 	public UnifyType setTypeParams(TypeParams newTp) {
-		if(newTp.size() == 0)
-			throw new IllegalArgumentException("Function types need at least one type parameter");
-		return new FunNType(newTp);
+		return getFunNType(newTp);
 	}
 
 	public int getN() {
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/Node.java b/src/de/dhbwstuttgart/typeinference/unify/model/Node.java
index 7010ec32..d338d16b 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/Node.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/Node.java
@@ -4,7 +4,7 @@ import java.util.HashSet;
 import java.util.Set;
 import java.util.stream.Collectors;
 
-public class Node<T> {
+class Node<T> {
 	private T content;
 	
 	private HashSet<Node<T>> predecessors = new HashSet<>();
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/Unifier.java b/src/de/dhbwstuttgart/typeinference/unify/model/Unifier.java
index a46ee6d3..33f9daec 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/Unifier.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/Unifier.java
@@ -45,7 +45,7 @@ public class Unifier implements Function<UnifyType, UnifyType> /*, Set<MPair>*/
 		return substitutions.containsKey(t);
 	}
 	
-	public UnifyType getSubstitute(UnifyType t) {
+	public UnifyType getSubstitute(PlaceholderType t) {
 		return substitutions.get(t);
 	}
 	
diff --git a/test/unify/UnifyTest.java b/test/unify/UnifyTest.java
index 0ee466e4..3d091f5e 100644
--- a/test/unify/UnifyTest.java
+++ b/test/unify/UnifyTest.java
@@ -380,13 +380,39 @@ public class UnifyTest extends Unify {
 		
 		//System.out.println(actual);
 		//Assert.assertEquals(actual, expected);
-
-		
 	}
 	
 	@Test
 	public void unifyTestComplex() {
+		/*
+		 * INIT
+		 */
+		TypeFactory tf = new TypeFactory();
+		FiniteClosureBuilder fcb = new FiniteClosureBuilder();
+
+		UnifyType tphT = tf.getPlaceholderType("T");
+		UnifyType vector = tf.getSimpleType("Vector", tphT);
+		UnifyType number = tf.getSimpleType("Number");
+		UnifyType integer = tf.getSimpleType("Integer");
+		UnifyType object = tf.getSimpleType("Object");
+		UnifyType matrix = tf.getSimpleType("Matrix");
+		UnifyType vectorvectorint = tf.getSimpleType("Vector", tf.getSimpleType("Vector", integer));
+
 		
+		fcb.add(integer, number);
+		fcb.add(matrix, vectorvectorint);
+		fcb.add(vector, object);
+		
+		IFiniteClosure fc = fcb.getFiniteClosure();
+		
+		Set<UnifyPair> eq = new HashSet<UnifyPair>();
+		eq.add(new UnifyPair(tf.getSimpleType("Matrix"), tf.getSimpleType("Vector", tf.getPlaceholderType("a")), PairOperator.SMALLERDOT));
+
+		Set<Set<UnifyPair>> expected = new HashSet<>();
+		Set<Set<UnifyPair>> actual = unify(eq, fc);
+		
+		System.out.println("Test Matrix:");
+		System.out.println(actual);
 	}
 	
 	@Test