theorem oreq1i (a b c: wff): $ a <-> b $ > $ a \/ c <-> b \/ c $;
| Step | Hyp | Ref | Expression |
|---|
| 1 |
|
id |
(a <-> b) -> (a <-> b) |
| 2 |
1 |
oreq1d |
(a <-> b) -> (a \/ c <-> b \/ c) |
| 3 |
|
hyp h |
a <-> b |
| 4 |
2, 3 |
ax_mp |
a \/ c <-> b \/ c |
Axiom use
axs_prop_calc
(ax_1,
ax_2,
ax_3,
ax_mp)