unfold DistSingle_G2, DistSingle_G3_c1.
comp_swap_r.
comp_skip.
comp_simp.
comp_skip.
comp_skip.
eapply hybrid_replace_c1_equiv.
eapply RndNat_support_lt; intuition.
Qed.

Theorem compMap_computeHybrid_0_equiv :
forall s_A a,
Pr  [b <-$ compMap B_EqDec (fun _ : nat => (c2 a)) (forNats n); A2 s_A b ] ==
Pr  [x <-$ computeHybrid n 0 a; A2 s_A x ].