added mutant 3

mutants/mutant-3/swen90006/machine/Machine.java

@@ -93,7 +93,7 @@ public class Machine
   private void do_store(int a, int offs, int b)  {
     if (regs[a] + offs > MAX_ADDR){
       /* no op */
-    }else if(regs[a] + offs < 0){
+    }else if(regs[a] + offs > 0){
       /* no op */
     }else{
       memory[regs[a] + offs] = regs[b];