fact: Definition try_pre : pre := fun i => exists (Vi : valid i) (Pi : i \In pre_of e), (forall y m, prog_of e _ Vi Pi (Val y) m -> pre_of (e1 y) m) /\ forall ex m, prog_of e _ Vi Pi (Exn ex) m -> pre_of (e2 ex) m.
imports: mathcomp(ssreflect ssrbool ssrfun ssrnat eqtype seq) pcm(options axioms pred prelude) pcm(pcm unionmap heap) htt(domain)