Theorem mt ≪ | index | src | ≫

theorem mt (a b: wff): $ b -> a $ > $ ~a $ > $ ~b $;

Step	Hyp	Ref	Expression
1		con3	(b -> a) -> ~a -> ~b
2		hyp h1	b -> a
3	1, 2	ax_mp	~a -> ~b
4		hyp h2	~a
5	3, 4	ax_mp	~b

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)