theorem subeq1 (_a1 _a2 b: nat): $ _a1 = _a2 -> _a1 - b = _a2 - b $;
| Step | Hyp | Ref | Expression |
|---|
| 1 |
|
id |
_a1 = _a2 -> _a1 = _a2 |
| 2 |
1 |
subeq1d |
_a1 = _a2 -> _a1 - b = _a2 - b |
Axiom use
axs_prop_calc
(ax_1,
ax_2,
ax_3,
ax_mp,
itru),
axs_pred_calc
(ax_gen,
ax_4,
ax_5,
ax_6,
ax_7,
ax_10,
ax_11,
ax_12),
axs_set
(elab,
ax_8),
axs_the
(theid,
the0),
axs_peano
(addeq)