Local Open Scope logic.
Require Export mc_reify.reify.
Require Export MirrorCore.RTac.Repeat.
Require Export MirrorCore.RTac.Try.
Require Export MirrorCore.RTac.First.
Require Export mc_reify.funcs.
Require Export mc_reify.reflexivity_tacs.

Lemma msubst_efield_denote_cons_union: forall fld efs T1 T2 gfs,
msubst_efield_denote T1 T2 efs = Some gfs ->
msubst_efield_denote T1 T2 (eUnionField fld :: efs) = Some (UnionField fld :: gfs).