Section effsemlemmas.
Context {G C:Type} (Sem: @EffectSem G C) (g:G).

Lemma effstep_sub: forall U V c m c' m'
(UV: forall b ofs, U b ofs = true -> V b ofs = true),
(effstep Sem g U c m c' m' -> effstep Sem g V c m c' m').