End FORWARD_SIMULATIONS.

(* Specifications: *)
Theorem forward_simulation_behavior_improves:
forall L1 L2, forward_simulation L1 L2 ->
forall beh1, program_behaves L1 beh1 ->
exists beh2, program_behaves L2 beh2 /\ behavior_improves beh1 beh2.
Corollary forward_simulation_same_safe_behavior:
forall L1 L2, forward_simulation L1 L2 ->
forall beh,
program_behaves L1 beh -> not_wrong beh ->
program_behaves L2 beh.