Notation corestepN := (corestepN (AsmContext.coarse_semantics initU)).

Lemma cmachine_step_invariant: forall tpc mc trc tpc' mc' trc' tpc'' trc'' mc'' U U' U'' n (HstepN: corestepN n (U, trc, tpc) mc (U', trc',tpc') mc') (Hstep: cmachine_step (U', trc', tpc') mc' (U'',trc'', tpc'') mc''), invariant tpc.