(* First algorithm of [Sheeran+ 2000]. *)
Definition sheeran1_post (I : prop) (T : trans) (P : prop) (k: nat) : Prop :=
safety_nth_conj I T P k /\
(lasso_fwd_conj I T k \/ lasso_bwd_conj T P k).
Set SMT Solver "z3".
Set SMT Debug.

Axiom by_smt : forall P : Prop, P.