intuition.
specialize (evalDist_getSupport_perm_id c (ret a)); intuition.
assert (forall a0 : A, evalDist c a0 == evalDist (ret a) a0).
intuition.
case_eq (eqb a a0); intuition.
rewrite eqb_leibniz in H2.
subst.
simpl.
destruct (EqDec_dec eqd a0 a0); intuition.
simpl.
assert (evalDist c a0 == 0).
eapply evalDist_1_0; intuition.
eapply H0.
subst.
rewrite eqb_refl in H2.
discriminate.
rewrite H3.
destruct ( EqDec_dec eqd a a0); subst; intuition.
rewrite eqb_refl in H2.
discriminate.
intuition.
simpl in *.
eapply Permutation_length_1_inv.
eapply Permutation_sym.
trivial.
Qed.

Theorem evalDist_bool_equiv_all :
forall (c1 c2 : Comp bool),
well_formed_comp c1 ->
well_formed_comp c2 ->
Pr[c1] == Pr[c2] ->
(forall b, evalDist c1 b == evalDist c2 b).