Theorem orim2d ≪ | index | src | ≫

theorem orim2d (a b c d: wff): $ a -> c -> d $ > $ a -> b \/ c -> b \/ d $;

Step	Hyp	Ref	Expression
1		idd	a -> b -> b
2		hyp h	a -> c -> d
3	1, 2	orimd	a -> b \/ c -> b \/ d

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)