Theorem casesda | index | src |

theorem casesda (a b c: wff): $ a /\ b -> c $ > $ a /\ ~b -> c $ > $ a -> c $;
StepHypRefExpression
1 hyp h1
a /\ b -> c
2 1 exp
a -> b -> c
3 hyp h2
a /\ ~b -> c
4 3 exp
a -> ~b -> c
5 2, 4 casesd
a -> c

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)