Theorem imim1i ≪ | index | src | ≫ 

theorem imim1i (a b c: wff): $ a -> b $ > $ (b -> c) -> a -> c $;
StepHypRefExpression
1 imim1 
(a -> b) -> (b -> c) -> a -> c
2 hyp h 
a -> b
3 1, 2 ax_mp 
(b -> c) -> a -> c

Axiom use

axs_prop_calc (ax_1, ax_2, ax_mp)