Instance EqDec_pshare : EqDec pshare := pshare_eq_dec.Definition pfullshare : pshare :=
  mk_lifted fullshare top_share_nonunit.

Lemma pshare_pjoin_full_false4: forall (p1: pshare) pp sh3, join (mk_lifted Share.top pp) p1 sh3 -> False.