Module unique := fc_unique wf subst.
Set Bullet Behavior "Strict Subproofs".
Set Implicit Arguments.
(* This version is just for "head reduction." *)

Lemma open_a_Conv : forall a b g,
open_tm_wrt_tm (a_Conv a g) b =
a_Conv (open_tm_wrt_tm a b) (open_co_wrt_tm g b).