unfold evalDet_equiv. intuition.
eapply H; trivial.
eapply H; trivial.
Qed.

Theorem evalDet_steps_bind_done_inv_h : forall (A : Set)(x y : comp_state A),
evalDet_steps x y ->
forall (B : Set)(c1 : Comp B)(c2 : B -> Comp A) s s' a,
x = (cs_more (Bind c1 c2) s) ->
y = (cs_done a s') ->
exists b s'', evalDet_steps (cs_more c1 s) (cs_done b s'') /\
evalDet_steps (cs_more (c2 b) s'') (cs_done a s').