Theorem exp ≪ | index | src | ≫ 

theorem exp (a b c: wff): $ a /\ b -> c $ > $ a -> b -> c $;
StepHypRefExpression
1 hyp h 
a /\ b -> c
2 ian 
a -> b -> a /\ b
3 1, 2 syl6 
a -> b -> c

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)