Section emptyset_subset_everything_2.
Variable B : Ens.
Hypothesis h : IN B EmptySet.
Let step1 : False. Proof EmptySet_th1 B h.
Proof false_implies_everything (IN B A) step1.
End emptyset_subset_everything_2.
Let step2 : forall (B : Ens) (h : IN B EmptySet), IN B A.
Proof emptyset_subset_everything_2_Out.
Proof step2.
End emptyset_subset_everything.

Theorem EmptySet_th2 : forall A : Ens, SUB EmptySet A.