End EXT_SIMULATION_STAR.
Section EXT_SIMULATION_PLUS.
Variable measure: C1 -> nat.
Hypothesis ext_plus_simulation:
forall c1 m1 c1' m1', corestep Sem1 ge1 c1 m1 c1' m1'  ->
forall c2 m2, match_states c1 c1 m1 c2 m2 ->
exists c2', exists m2',
corestep_plus Sem2 ge2 c2 m2 c2' m2' /\
match_states c1' c1' m1' c2' m2'.

Lemma ext_simulation_plus:
Forward_simulation_ext.Forward_simulation_extends Sem1 Sem2 ge1 ge2 entry_points.