p 0 0 p s X X leq 0 Y true leq s X 0 false leq s X s Y leq X Y if true X Y X if false X Y Y diff X Y if leq X Y 0 s diff p X Y 2.2 diff X Y if leq X Y 0 s diff p X Y diff X Y p X diff X Y leq X Y leq s X s Y leq X Y diff X Y diff p X Y true diff X Y diff p X Y true Failed! NaTT certifiable-1.6