Definition blockslice_mpred_rmap:
  forall S (Sdec: forall b, {S b}+{~S b}) P phi,
   blockslice_mpred S P -> P phi -> blockslice_rmap S phi.

Lemma rev_prog_vars': forall {F V} vl, rev (@prog_vars' F V vl) = prog_vars' (rev vl).