theorem dropeq (_l1 _l2 _n1 _n2: nat):
$ _l1 = _l2 -> _n1 = _n2 -> drop _l1 _n1 = drop _l2 _n2 $;
| Step | Hyp | Ref | Expression |
|---|
| 1 |
|
anl |
_l1 = _l2 /\ _n1 = _n2 -> _l1 = _l2 |
| 2 |
|
anr |
_l1 = _l2 /\ _n1 = _n2 -> _n1 = _n2 |
| 3 |
1, 2 |
dropeqd |
_l1 = _l2 /\ _n1 = _n2 -> drop _l1 _n1 = drop _l2 _n2 |
| 4 |
3 |
exp |
_l1 = _l2 -> _n1 = _n2 -> drop _l1 _n1 = drop _l2 _n2 |
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
(peano2,
addeq,
muleq)