Theorem imim1d ≪ | index | src | ≫

theorem imim1d (a b c d: wff): $ a -> b -> c $ > $ a -> (c -> d) -> b -> d $;

Step	Hyp	Ref	Expression
1		imim1	(b -> c) -> (c -> d) -> b -> d
2		hyp h	a -> b -> c
3	1, 2	syl	a -> (c -> d) -> b -> d

Axiom use

axs_prop_calc (ax_1, ax_2, ax_mp)