diff --git a/src/de/dhbwstuttgart/typeinference/unify/Unifier.java b/src/de/dhbwstuttgart/typeinference/unify/Unifier.java
new file mode 100644
index 000000000..73478957c
--- /dev/null
+++ b/src/de/dhbwstuttgart/typeinference/unify/Unifier.java
@@ -0,0 +1,11 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import java.util.Vector;
+
+import de.dhbwstuttgart.typeinference.Pair;
+
+public interface Unifier {
+
+	public Vector<Vector<Pair>> unify (Vector<Pair> E);
+
+}
diff --git a/test/plugindevelopment/TypeInsertTests/TypedMatrixTest.jav b/test/plugindevelopment/TypeInsertTests/TypedMatrixTest.jav
new file mode 100644
index 000000000..f2c5c3f58
--- /dev/null
+++ b/test/plugindevelopment/TypeInsertTests/TypedMatrixTest.jav
@@ -0,0 +1,35 @@
+import java.util.Vector;
+
+class Matrix extends Vector<Vector<Integer>> {
+
+	Matrix mul(Matrix m){
+		Matrix ret;
+		ret = new Matrix();
+		Integer i;
+		i = 0;
+		while(i < this.size()) {
+			Vector<Integer> v1;
+			Vector<Integer> v2;
+			v1 = this.elementAt(i);
+			v2 = new Vector<Integer>();
+			Integer j;
+			j = 0;
+			while(j < this.size()) {
+				erg;
+				erg = 0;
+				Integer k;
+				k = 0;
+				while(k < v1.size()) {
+					erg = erg + v1.elementAt(k).intValue() * m.elementAt(k).elementAt(j).intValue();
+					k++;
+				}
+				v2.addElement(new Integer(erg));
+				j++;
+			}
+			ret.addElement(v2);
+			i++;
+		}
+		return ret;
+	}
+	
+}
\ No newline at end of file
diff --git a/test/plugindevelopment/TypeInsertTests/TypedMatrixTest.java b/test/plugindevelopment/TypeInsertTests/TypedMatrixTest.java
new file mode 100644
index 000000000..810af9993
--- /dev/null
+++ b/test/plugindevelopment/TypeInsertTests/TypedMatrixTest.java
@@ -0,0 +1,16 @@
+package plugindevelopment.TypeInsertTests;
+
+import java.util.Vector;
+
+import org.junit.Test;
+
+public class TypedMatrixTest {
+	private static final String TEST_FILE = "TypedMatrixTest.jav";
+	
+	@Test
+	public void run(){
+		Vector<String> mustContain = new Vector<String>();
+		mustContain.add("Integer erg;");
+		MultipleTypesInsertTester.testSingleInsert(this.TEST_FILE, mustContain);
+	}
+}