theorem oreq2a (a b c: wff): $ (~a -> (b <-> c)) -> (a \/ b <-> a \/ c) $;
| Step | Hyp | Ref | Expression |
|---|
| 1 |
|
imeq2a |
(~a -> (b <-> c)) -> (~a -> b <-> ~a -> c) |
| 2 |
1 |
conv or |
(~a -> (b <-> c)) -> (a \/ b <-> a \/ c) |
Axiom use
axs_prop_calc
(ax_1,
ax_2,
ax_3,
ax_mp)