anchor.diff:              [|
                   ("RunTest.ycp", "RunTest.fxp");
               
  -                ("CombineAb.ycp",  "CombineAb.fxp");
  -                ("CombineBe.ycp",  "CombineBe.fxp");
  +                ("CombineAb.ycp", "CombineAb.fxp");
  +                ("CombineBe.ycp", "CombineBe.fxp");
               
                   ("whileA.ycp", "whileA.fxp");
                   ("whileB.ycp", "whileB.fxp");
  -                ("whileAB.ycp",  "whileAB.fxp");
  +                ("whileAB.ycp", "whileAB.fxp");
                   ("whileW.ycp", "whileW.fxp");
   
                   ("while+expr.ycp", "while+expr.fxp");
   
  -                ("ifA.ycp",   "ifA.fxp");
  +                ("ifA.ycp", "ifA.fxp");
                   ("ifB.ycp", "ifB.fxp");
                   ("ifAB.ycp", "ifAB.fxp");
                   ("ifW.ycp", "ifW.fxp");
   
  -                ("LowTreeAA.ycp",  "LowTreeAA.fxp");
  -                ("LowTreeAB.ycp",  "LowTreeAB.fxp");
  -                ("LowTreeBB.ycp",  "LowTreeBB.fxp");
  -                ("LowTreeBA.ycp",  "LowTreeBA.fxp");            
  -                ("LowTreeAbAb.ycp",  "LowTreeAbAb.fxp");
  -                ("LowTreeW.ycp",  "LowTreeW.fxp");
  +                ("LowTreeAA.ycp", "LowTreeAA.fxp");
  +                ("LowTreeAB.ycp", "LowTreeAB.fxp");
  +                ("LowTreeBB.ycp", "LowTreeBB.fxp");
  +                ("LowTreeBA.ycp", "LowTreeBA.fxp");
  +                ("LowTreeAbAb.ycp", "LowTreeAbAb.fxp");
  +                ("LowTreeW.ycp", "LowTreeW.fxp");
   
                   ("HardTreeAA.ycp", "HardTreeAA.fxp");
                   ("HardTreeBB.ycp", "HardTreeBB.fxp");
  
positive.code:             [|
                  (10, A, A, "RunTest.in", "RunTest.ycp");
              
                  (2, A, A, "Combine.in",  "CombineAb.ycp");
                  (10, A, A, "Combine.in",  "CombineBe.ycp");
              
                  (10, A, A, "while.in", "whileA.ycp");
                  (10, A, B, "while.in", "whileB.ycp");
                  (10, A, AB,"while.in",  "whileAB.ycp");
                  (5, A, AB, "while.in", "whileW.ycp");
              
                  (10, A, A, "while+expr.in", "while+expr.ycp");
  
                  (10, A, A, "if.in",   "ifA.ycp");
                  (10, B, A, "if.in", "ifB.ycp");
                  (10, AB, A,"if.in", "ifAB.ycp");
                  (5, AB, A, "if.in", "ifW.ycp");
  
                  (25, A, A, "LowTree.in",  "LowTreeAA.ycp");
                  (25, A, B, "LowTree.in",  "LowTreeAB.ycp");
                  (25, B, B, "LowTree.in",  "LowTreeBB.ycp");
                  (25, B, A, "LowTree.in",  "LowTreeBA.ycp");            
                  (25, AB, AB, "LowTree.in",  "LowTreeAbAb.ycp");
                  (20, A, A, "LowTree.in",  "LowTreeW.ycp");
  
                  (50, A, A, "HardTree.in", "HardTreeAA.ycp");
                  (50, B, B, "HardTree.in", "HardTreeBB.ycp");
  
negative.code:             [|
                  (10, A, A, "RunTest.in", "RunTest.fxp");
              
                  (2, A, A, "Combine.in", "CombineAb.fxp");
                  (10, A, A, "Combine.in", "CombineBe.fxp");
              
                  (10, A, A, "while.in", "whileA.fxp");
                  (10, A, B, "while.in", "whileB.fxp");
                  (10, A, AB,"while.in", "whileAB.fxp");
                  (5, A, AB, "while.in", "whileW.fxp");
              
                  (10, A, A, "while+expr.in", "while+expr.fxp");
  
                  (10, A, A, "If.in", "ifA.fxp");
                  (10, B, A, "If.in", "ifB.fxp");
                  (10, AB, A,"If.in", "ifAB.fxp");
                  (5, AB, A, "If.in", "ifW.fxp");
  
                  (25, A, A, "LowTree.in", "LowTreeAA.fxp");
                  (25, A, B, "LowTree.in", "LowTreeAB.fxp");
                  (25, B, B, "LowTree.in", "LowTreeBB.fxp");
                  (25, B, A, "LowTree.in", "LowTreeBA.fxp");            
                  (25, AB, AB, "LowTree.in", "LowTreeAbAb.fxp");
                  (20, A, A, "LowTree.in", "LowTreeW.fxp");
  
                  (50, A, A, "HardTree.in", "HardTreeAA.fxp");
                  (50, B, B, "HardTree.in", "HardTreeBB.fxp");
  