Ltac gather_entail :=
repeat match goal with
 | A := _ |- _ =>  clear A || (revert A; match goal with |- ?B => no_evars B end)
 | H : ?P |- _ =>
  match type of P with
  | Prop => match P with name _ => fail 2 | _ => revert H; match goal with |- ?B => no_evars B end end
  | _ => clear H || (revert H; match goal with |- ?B => no_evars B end)
  end
end;
repeat match goal with
 | x := ?X |- _ => is_evar X; clearbody x; revert x; apply EVAR_e
end;
repeat match goal with
  | H : name _ |- _ => revert H
 end.

Lemma EVAR_i: forall P: Prop, P -> EVAR P.