diff --git a/LernProgramm/testProgramm.java b/LernProgramm/testProgramm.java
index 48501cf..3c512d8 100644
--- a/LernProgramm/testProgramm.java
+++ b/LernProgramm/testProgramm.java
@@ -30,5 +30,12 @@ class testProgramm {
 	    int result = ProgrammMain.calculate("1010", "1011", '+');
 	    assertEquals(10101, result);
 	  }
-
+	  @Test
+	  public void testSubtraction() {
+	    int result = ProgrammMain.calculate("1010", "1011", '-');
+	    result++;
+	    if (result <0 || result >0) {
+	    	 assertTrue(true);
+	    }
+	  }
 }
diff --git a/bin/LernProgramm/testProgramm.class b/bin/LernProgramm/testProgramm.class
index 583d3d5..e8f86ae 100644
Binary files a/bin/LernProgramm/testProgramm.class and b/bin/LernProgramm/testProgramm.class differ