Theorem syl6 ≪ | index | src | ≫

theorem syl6 (a b c d: wff): $ c -> d $ > $ a -> b -> c $ > $ a -> b -> d $;

Step	Hyp	Ref	Expression
1		hyp h2	a -> b -> c
2		hyp h1	c -> d
3	2	a1i	a -> c -> d
4	1, 3	syld	a -> b -> d

Axiom use

axs_prop_calc (ax_1, ax_2, ax_mp)