Theorem sylib ≪ | index | src | ≫

theorem sylib (a b c: wff): $ b <-> c $ > $ a -> b $ > $ a -> c $;

Step	Hyp	Ref	Expression
1		hyp h1	b <-> c
2	1	bi1i	b -> c
3		hyp h2	a -> b
4	2, 3	syl	a -> c

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)