Design verification
Requirements of a design are formalized as predicates constraining the computation. E.g. two grant signals never given simultaneous access.
Example: Let us verify invariant in a design.
I(s) on a state S is invariant
I(pre) ? t(pre,post) ? I(post)
To show that ? (grl ? grr) is an invariant for arbiter, four implications must be shown. I.e. reql ? ?grr ? grl ? ? (grl ? grr)
Invariant: Sub set of state space containing initial state.
Further, there must not be any transition from a state with in
Hence, invariant describes properties that hold through