Section emptyset_subset_everything.
Variable A : Ens.
Section emptyset_subset_everything_2.
Variable B : Ens.
Hypothesis h : IN B EmptySet.
Let step1 : False. Proof EmptySet_th1 B h.

Lemma emptyset_subset_everything_2_Out : IN B A.
Proof false_implies_everything (IN B A) step1.