proposition: Theorem ceval_deterministic' : forall c st st1 st2, c / st \\ st1 -> c / st \\ st2 -> st1 = st2.
proof: Proof. intros c st st1 st2 He1 He2. apply ceval__ceval_step in He1. apply ceval__ceval_step in He2. inversion He1 as [i1 E1]. inversion He2 as [i2 E2]. apply ceval_step_more with (i2 := i1 + i2) in E1. apply ceval_step_more with (i2 := i1 + i2) in E2. rewrite E1 in E2. inversion E2. reflexivity. omega. omega. Qed.
imports: Coq.omega.Omega Coq.Arith.Arith Imp Maps