theorem snocne0 (a b: nat): $ a |> b != 0 $;
Step | Hyp | Ref | Expression |
1 |
|
len0 |
len 0 = 0 |
2 |
|
leneq |
a |> b = 0 -> len (a |> b) = len 0 |
3 |
1, 2 |
syl6eq |
a |> b = 0 -> len (a |> b) = 0 |
4 |
|
sucne0 |
len (a |> b) = suc (len a) -> len (a |> b) != 0 |
5 |
4 |
conv ne |
len (a |> b) = suc (len a) -> ~len (a |> b) = 0 |
6 |
|
snoclen |
len (a |> b) = suc (len a) |
7 |
5, 6 |
ax_mp |
~len (a |> b) = 0 |
8 |
3, 7 |
mt |
~a |> b = 0 |
9 |
8 |
conv ne |
a |> b != 0 |
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
(peano1,
peano2,
peano5,
addeq,
muleq,
add0,
addS,
mul0,
mulS)