Understanding Frama-C slicer results

Question

I\'d like to know if it\'s possible to do some kind of forward conditioned slicing with Frama-C and I\'m playing with some examples to understand how one could achieve this.

Answer 1

This has no relevance whatsoever with your main question, but your ensures a == \old(a) clause is not doing what you expect. If you pretty-print your source code with option -print, you will see it has been silently transformed into ensures \old(a) == \old(a).

The ACSL language does not permit referring about the value of formal variables in the post-state, mostly because this is meaningless from the point of view of the caller. (The stack frame of the callee is popped after the call terminates.)