Proof of Theorem pythagtriplem2
Step | Hyp | Ref
| Expression |
1 | | ovex 7265 |
. . . . . . . 8
⊢ (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∈ V |
2 | | ovex 7265 |
. . . . . . . 8
⊢ (𝑘 · (2 · (𝑚 · 𝑛))) ∈ V |
3 | | preq12bg 4779 |
. . . . . . . 8
⊢ (((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) ∧ ((𝑘 · ((𝑚↑2) − (𝑛↑2))) ∈ V ∧ (𝑘 · (2 · (𝑚 · 𝑛))) ∈ V)) → ({𝐴, 𝐵} = {(𝑘 · ((𝑚↑2) − (𝑛↑2))), (𝑘 · (2 · (𝑚 · 𝑛)))} ↔ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))))))) |
4 | 1, 2, 3 | mpanr12 705 |
. . . . . . 7
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) → ({𝐴, 𝐵} = {(𝑘 · ((𝑚↑2) − (𝑛↑2))), (𝑘 · (2 · (𝑚 · 𝑛)))} ↔ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))))))) |
5 | 4 | anbi1d 633 |
. . . . . 6
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) → (({𝐴, 𝐵} = {(𝑘 · ((𝑚↑2) − (𝑛↑2))), (𝑘 · (2 · (𝑚 · 𝑛)))} ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ (((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
6 | | andir 1009 |
. . . . . . 7
⊢ ((((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ (((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛)))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ((𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2)))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
7 | | df-3an 1091 |
. . . . . . . 8
⊢ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛)))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) |
8 | | df-3an 1091 |
. . . . . . . 8
⊢ ((𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ ((𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2)))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) |
9 | 7, 8 | orbi12i 915 |
. . . . . . 7
⊢ (((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) ↔ (((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛)))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ((𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2)))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
10 | 6, 9 | bitr4i 281 |
. . . . . 6
⊢ ((((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
11 | 5, 10 | bitrdi 290 |
. . . . 5
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) → (({𝐴, 𝐵} = {(𝑘 · ((𝑚↑2) − (𝑛↑2))), (𝑘 · (2 · (𝑚 · 𝑛)))} ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))))) |
12 | 11 | rexbidv 3224 |
. . . 4
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) →
(∃𝑘 ∈ ℕ
({𝐴, 𝐵} = {(𝑘 · ((𝑚↑2) − (𝑛↑2))), (𝑘 · (2 · (𝑚 · 𝑛)))} ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ ∃𝑘 ∈ ℕ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))))) |
13 | 12 | 2rexbidv 3227 |
. . 3
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) →
(∃𝑛 ∈ ℕ
∃𝑚 ∈ ℕ
∃𝑘 ∈ ℕ
({𝐴, 𝐵} = {(𝑘 · ((𝑚↑2) − (𝑛↑2))), (𝑘 · (2 · (𝑚 · 𝑛)))} ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ ∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))))) |
14 | | r19.43 3277 |
. . . . 5
⊢
(∃𝑘 ∈
ℕ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) ↔ (∃𝑘 ∈ ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
15 | 14 | 2rexbii 3177 |
. . . 4
⊢
(∃𝑛 ∈
ℕ ∃𝑚 ∈
ℕ ∃𝑘 ∈
ℕ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) ↔ ∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ (∃𝑘 ∈ ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
16 | | r19.43 3277 |
. . . . 5
⊢
(∃𝑚 ∈
ℕ (∃𝑘 ∈
ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) ↔ (∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
17 | 16 | rexbii 3176 |
. . . 4
⊢
(∃𝑛 ∈
ℕ ∃𝑚 ∈
ℕ (∃𝑘 ∈
ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) ↔ ∃𝑛 ∈ ℕ (∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
18 | | r19.43 3277 |
. . . 4
⊢
(∃𝑛 ∈
ℕ (∃𝑚 ∈
ℕ ∃𝑘 ∈
ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) ↔ (∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
19 | 15, 17, 18 | 3bitri 300 |
. . 3
⊢
(∃𝑛 ∈
ℕ ∃𝑚 ∈
ℕ ∃𝑘 ∈
ℕ ((𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) ↔ (∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))))) |
20 | 13, 19 | bitrdi 290 |
. 2
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) →
(∃𝑛 ∈ ℕ
∃𝑚 ∈ ℕ
∃𝑘 ∈ ℕ
({𝐴, 𝐵} = {(𝑘 · ((𝑚↑2) − (𝑛↑2))), (𝑘 · (2 · (𝑚 · 𝑛)))} ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ (∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))))) |
21 | | pythagtriplem1 16397 |
. . . 4
⊢
(∃𝑛 ∈
ℕ ∃𝑚 ∈
ℕ ∃𝑘 ∈
ℕ (𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) → ((𝐴↑2) + (𝐵↑2)) = (𝐶↑2)) |
22 | 21 | a1i 11 |
. . 3
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) →
(∃𝑛 ∈ ℕ
∃𝑚 ∈ ℕ
∃𝑘 ∈ ℕ
(𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) → ((𝐴↑2) + (𝐵↑2)) = (𝐶↑2))) |
23 | | 3ancoma 1100 |
. . . . . . 7
⊢ ((𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ (𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) |
24 | 23 | rexbii 3176 |
. . . . . 6
⊢
(∃𝑘 ∈
ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ ∃𝑘 ∈ ℕ (𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) |
25 | 24 | 2rexbii 3177 |
. . . . 5
⊢
(∃𝑛 ∈
ℕ ∃𝑚 ∈
ℕ ∃𝑘 ∈
ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ↔ ∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) |
26 | | pythagtriplem1 16397 |
. . . . 5
⊢
(∃𝑛 ∈
ℕ ∃𝑚 ∈
ℕ ∃𝑘 ∈
ℕ (𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) → ((𝐵↑2) + (𝐴↑2)) = (𝐶↑2)) |
27 | 25, 26 | sylbi 220 |
. . . 4
⊢
(∃𝑛 ∈
ℕ ∃𝑚 ∈
ℕ ∃𝑘 ∈
ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) → ((𝐵↑2) + (𝐴↑2)) = (𝐶↑2)) |
28 | | nncn 11863 |
. . . . . . 7
⊢ (𝐴 ∈ ℕ → 𝐴 ∈
ℂ) |
29 | 28 | sqcld 13742 |
. . . . . 6
⊢ (𝐴 ∈ ℕ → (𝐴↑2) ∈
ℂ) |
30 | | nncn 11863 |
. . . . . . 7
⊢ (𝐵 ∈ ℕ → 𝐵 ∈
ℂ) |
31 | 30 | sqcld 13742 |
. . . . . 6
⊢ (𝐵 ∈ ℕ → (𝐵↑2) ∈
ℂ) |
32 | | addcom 11043 |
. . . . . 6
⊢ (((𝐴↑2) ∈ ℂ ∧
(𝐵↑2) ∈ ℂ)
→ ((𝐴↑2) + (𝐵↑2)) = ((𝐵↑2) + (𝐴↑2))) |
33 | 29, 31, 32 | syl2an 599 |
. . . . 5
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) → ((𝐴↑2) + (𝐵↑2)) = ((𝐵↑2) + (𝐴↑2))) |
34 | 33 | eqeq1d 2740 |
. . . 4
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) → (((𝐴↑2) + (𝐵↑2)) = (𝐶↑2) ↔ ((𝐵↑2) + (𝐴↑2)) = (𝐶↑2))) |
35 | 27, 34 | syl5ibr 249 |
. . 3
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) →
(∃𝑛 ∈ ℕ
∃𝑚 ∈ ℕ
∃𝑘 ∈ ℕ
(𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) → ((𝐴↑2) + (𝐵↑2)) = (𝐶↑2))) |
36 | 22, 35 | jaod 859 |
. 2
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) →
((∃𝑛 ∈ ℕ
∃𝑚 ∈ ℕ
∃𝑘 ∈ ℕ
(𝐴 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐵 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) ∨ ∃𝑛 ∈ ℕ ∃𝑚 ∈ ℕ ∃𝑘 ∈ ℕ (𝐴 = (𝑘 · (2 · (𝑚 · 𝑛))) ∧ 𝐵 = (𝑘 · ((𝑚↑2) − (𝑛↑2))) ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2))))) → ((𝐴↑2) + (𝐵↑2)) = (𝐶↑2))) |
37 | 20, 36 | sylbid 243 |
1
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ) →
(∃𝑛 ∈ ℕ
∃𝑚 ∈ ℕ
∃𝑘 ∈ ℕ
({𝐴, 𝐵} = {(𝑘 · ((𝑚↑2) − (𝑛↑2))), (𝑘 · (2 · (𝑚 · 𝑛)))} ∧ 𝐶 = (𝑘 · ((𝑚↑2) + (𝑛↑2)))) → ((𝐴↑2) + (𝐵↑2)) = (𝐶↑2))) |