Step | Hyp | Ref
| Expression |
1 | | 0cnsuc 4402 |
. . . . . . . 8
⊢ (x +c 1c) ≠
0c |
2 | 1 | necomi 2599 |
. . . . . . 7
⊢
0c ≠ (x
+c 1c) |
3 | | df-ne 2519 |
. . . . . . 7
⊢
(0c ≠ (x
+c 1c) ↔ ¬ 0c =
(x +c
1c)) |
4 | 2, 3 | mpbi 199 |
. . . . . 6
⊢ ¬
0c = (x
+c 1c) |
5 | | addcid1 4406 |
. . . . . . . . 9
⊢ (A +c 0c) =
A |
6 | 5 | eqcomi 2357 |
. . . . . . . 8
⊢ A = (A
+c 0c) |
7 | | addcass 4416 |
. . . . . . . 8
⊢ ((A +c x) +c 1c) =
(A +c (x +c
1c)) |
8 | 6, 7 | eqeq12i 2366 |
. . . . . . 7
⊢ (A = ((A
+c x)
+c 1c) ↔ (A +c 0c) =
(A +c (x +c
1c))) |
9 | | simpll 730 |
. . . . . . . 8
⊢ (((A ∈ Nn ∧ A ≠ ∅) ∧ x ∈ Nn ) → A ∈ Nn ) |
10 | | peano1 4403 |
. . . . . . . . 9
⊢
0c ∈ Nn |
11 | 10 | a1i 10 |
. . . . . . . 8
⊢ (((A ∈ Nn ∧ A ≠ ∅) ∧ x ∈ Nn ) →
0c ∈ Nn ) |
12 | | peano2 4404 |
. . . . . . . . 9
⊢ (x ∈ Nn → (x
+c 1c) ∈
Nn ) |
13 | 12 | adantl 452 |
. . . . . . . 8
⊢ (((A ∈ Nn ∧ A ≠ ∅) ∧ x ∈ Nn ) →
(x +c
1c) ∈ Nn ) |
14 | 5 | neeq1i 2527 |
. . . . . . . . . 10
⊢ ((A +c 0c) ≠
∅ ↔ A ≠ ∅) |
15 | 14 | biimpri 197 |
. . . . . . . . 9
⊢ (A ≠ ∅ →
(A +c
0c) ≠ ∅) |
16 | 15 | ad2antlr 707 |
. . . . . . . 8
⊢ (((A ∈ Nn ∧ A ≠ ∅) ∧ x ∈ Nn ) →
(A +c
0c) ≠ ∅) |
17 | | preaddccan2 4456 |
. . . . . . . 8
⊢ (((A ∈ Nn ∧
0c ∈ Nn ∧ (x +c 1c) ∈ Nn ) ∧ (A
+c 0c) ≠ ∅) → ((A
+c 0c) = (A +c (x +c 1c)) ↔
0c = (x
+c 1c))) |
18 | 9, 11, 13, 16, 17 | syl31anc 1185 |
. . . . . . 7
⊢ (((A ∈ Nn ∧ A ≠ ∅) ∧ x ∈ Nn ) →
((A +c
0c) = (A
+c (x
+c 1c)) ↔ 0c =
(x +c
1c))) |
19 | 8, 18 | syl5bb 248 |
. . . . . 6
⊢ (((A ∈ Nn ∧ A ≠ ∅) ∧ x ∈ Nn ) →
(A = ((A +c x) +c 1c) ↔
0c = (x
+c 1c))) |
20 | 4, 19 | mtbiri 294 |
. . . . 5
⊢ (((A ∈ Nn ∧ A ≠ ∅) ∧ x ∈ Nn ) → ¬
A = ((A
+c x)
+c 1c)) |
21 | 20 | nrexdv 2718 |
. . . 4
⊢ ((A ∈ Nn ∧ A ≠ ∅) →
¬ ∃x
∈ Nn A = ((A
+c x)
+c 1c)) |
22 | 21 | ex 423 |
. . 3
⊢ (A ∈ Nn → (A ≠
∅ → ¬ ∃x ∈ Nn A = ((A
+c x)
+c 1c))) |
23 | | imnan 411 |
. . 3
⊢ ((A ≠ ∅ →
¬ ∃x
∈ Nn A = ((A
+c x)
+c 1c)) ↔ ¬ (A ≠ ∅ ∧ ∃x ∈ Nn A = ((A +c x) +c
1c))) |
24 | 22, 23 | sylib 188 |
. 2
⊢ (A ∈ Nn → ¬ (A
≠ ∅ ∧
∃x ∈ Nn A = ((A
+c x)
+c 1c))) |
25 | | opkltfing 4450 |
. . 3
⊢ ((A ∈ Nn ∧ A ∈ Nn ) → (⟪A, A⟫
∈ <fin ↔ (A ≠ ∅ ∧ ∃x ∈ Nn A = ((A +c x) +c
1c)))) |
26 | 25 | anidms 626 |
. 2
⊢ (A ∈ Nn → (⟪A, A⟫
∈ <fin ↔ (A ≠ ∅ ∧ ∃x ∈ Nn A = ((A +c x) +c
1c)))) |
27 | 24, 26 | mtbird 292 |
1
⊢ (A ∈ Nn → ¬ ⟪A, A⟫
∈ <fin ) |