Proof of Theorem sqpweven
| Step | Hyp | Ref
| Expression |
| 1 | | oddpwdc.j |
. . . . . . . 8
⊢ 𝐽 = {𝑧 ∈ ℕ ∣ ¬ 2 ∥ 𝑧} |
| 2 | | oddpwdc.f |
. . . . . . . 8
⊢ 𝐹 = (𝑥 ∈ 𝐽, 𝑦 ∈ ℕ0 ↦
((2↑𝑦) · 𝑥)) |
| 3 | 1, 2 | oddpwdc 12342 |
. . . . . . 7
⊢ 𝐹:(𝐽 × ℕ0)–1-1-onto→ℕ |
| 4 | | f1ocnv 5517 |
. . . . . . 7
⊢ (𝐹:(𝐽 × ℕ0)–1-1-onto→ℕ → ◡𝐹:ℕ–1-1-onto→(𝐽 ×
ℕ0)) |
| 5 | | f1of 5504 |
. . . . . . 7
⊢ (◡𝐹:ℕ–1-1-onto→(𝐽 × ℕ0) → ◡𝐹:ℕ⟶(𝐽 ×
ℕ0)) |
| 6 | 3, 4, 5 | mp2b 8 |
. . . . . 6
⊢ ◡𝐹:ℕ⟶(𝐽 ×
ℕ0) |
| 7 | 6 | ffvelcdmi 5696 |
. . . . 5
⊢ (𝐴 ∈ ℕ → (◡𝐹‘𝐴) ∈ (𝐽 ×
ℕ0)) |
| 8 | | xp2nd 6224 |
. . . . 5
⊢ ((◡𝐹‘𝐴) ∈ (𝐽 × ℕ0) →
(2nd ‘(◡𝐹‘𝐴)) ∈
ℕ0) |
| 9 | 7, 8 | syl 14 |
. . . 4
⊢ (𝐴 ∈ ℕ →
(2nd ‘(◡𝐹‘𝐴)) ∈
ℕ0) |
| 10 | 9 | nn0zd 9446 |
. . 3
⊢ (𝐴 ∈ ℕ →
(2nd ‘(◡𝐹‘𝐴)) ∈ ℤ) |
| 11 | | 2nn 9152 |
. . . . 5
⊢ 2 ∈
ℕ |
| 12 | 11 | a1i 9 |
. . . 4
⊢ (𝐴 ∈ ℕ → 2 ∈
ℕ) |
| 13 | 12 | nnzd 9447 |
. . 3
⊢ (𝐴 ∈ ℕ → 2 ∈
ℤ) |
| 14 | | dvdsmul2 11979 |
. . 3
⊢
(((2nd ‘(◡𝐹‘𝐴)) ∈ ℤ ∧ 2 ∈ ℤ)
→ 2 ∥ ((2nd ‘(◡𝐹‘𝐴)) · 2)) |
| 15 | 10, 13, 14 | syl2anc 411 |
. 2
⊢ (𝐴 ∈ ℕ → 2 ∥
((2nd ‘(◡𝐹‘𝐴)) · 2)) |
| 16 | | xp1st 6223 |
. . . . . . . . . 10
⊢ ((◡𝐹‘𝐴) ∈ (𝐽 × ℕ0) →
(1st ‘(◡𝐹‘𝐴)) ∈ 𝐽) |
| 17 | 7, 16 | syl 14 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℕ →
(1st ‘(◡𝐹‘𝐴)) ∈ 𝐽) |
| 18 | | breq2 4037 |
. . . . . . . . . . . 12
⊢ (𝑧 = (1st ‘(◡𝐹‘𝐴)) → (2 ∥ 𝑧 ↔ 2 ∥ (1st
‘(◡𝐹‘𝐴)))) |
| 19 | 18 | notbid 668 |
. . . . . . . . . . 11
⊢ (𝑧 = (1st ‘(◡𝐹‘𝐴)) → (¬ 2 ∥ 𝑧 ↔ ¬ 2 ∥
(1st ‘(◡𝐹‘𝐴)))) |
| 20 | 19, 1 | elrab2 2923 |
. . . . . . . . . 10
⊢
((1st ‘(◡𝐹‘𝐴)) ∈ 𝐽 ↔ ((1st ‘(◡𝐹‘𝐴)) ∈ ℕ ∧ ¬ 2 ∥
(1st ‘(◡𝐹‘𝐴)))) |
| 21 | 20 | simplbi 274 |
. . . . . . . . 9
⊢
((1st ‘(◡𝐹‘𝐴)) ∈ 𝐽 → (1st ‘(◡𝐹‘𝐴)) ∈ ℕ) |
| 22 | 17, 21 | syl 14 |
. . . . . . . 8
⊢ (𝐴 ∈ ℕ →
(1st ‘(◡𝐹‘𝐴)) ∈ ℕ) |
| 23 | 22 | nnsqcld 10786 |
. . . . . . 7
⊢ (𝐴 ∈ ℕ →
((1st ‘(◡𝐹‘𝐴))↑2) ∈ ℕ) |
| 24 | 20 | simprbi 275 |
. . . . . . . . . 10
⊢
((1st ‘(◡𝐹‘𝐴)) ∈ 𝐽 → ¬ 2 ∥ (1st
‘(◡𝐹‘𝐴))) |
| 25 | 17, 24 | syl 14 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℕ → ¬ 2
∥ (1st ‘(◡𝐹‘𝐴))) |
| 26 | | 2prm 12295 |
. . . . . . . . . 10
⊢ 2 ∈
ℙ |
| 27 | 22 | nnzd 9447 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℕ →
(1st ‘(◡𝐹‘𝐴)) ∈ ℤ) |
| 28 | | euclemma 12314 |
. . . . . . . . . . 11
⊢ ((2
∈ ℙ ∧ (1st ‘(◡𝐹‘𝐴)) ∈ ℤ ∧ (1st
‘(◡𝐹‘𝐴)) ∈ ℤ) → (2 ∥
((1st ‘(◡𝐹‘𝐴)) · (1st ‘(◡𝐹‘𝐴))) ↔ (2 ∥ (1st
‘(◡𝐹‘𝐴)) ∨ 2 ∥ (1st
‘(◡𝐹‘𝐴))))) |
| 29 | | oridm 758 |
. . . . . . . . . . 11
⊢ ((2
∥ (1st ‘(◡𝐹‘𝐴)) ∨ 2 ∥ (1st
‘(◡𝐹‘𝐴))) ↔ 2 ∥ (1st
‘(◡𝐹‘𝐴))) |
| 30 | 28, 29 | bitrdi 196 |
. . . . . . . . . 10
⊢ ((2
∈ ℙ ∧ (1st ‘(◡𝐹‘𝐴)) ∈ ℤ ∧ (1st
‘(◡𝐹‘𝐴)) ∈ ℤ) → (2 ∥
((1st ‘(◡𝐹‘𝐴)) · (1st ‘(◡𝐹‘𝐴))) ↔ 2 ∥ (1st
‘(◡𝐹‘𝐴)))) |
| 31 | 26, 27, 27, 30 | mp3an2i 1353 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℕ → (2
∥ ((1st ‘(◡𝐹‘𝐴)) · (1st ‘(◡𝐹‘𝐴))) ↔ 2 ∥ (1st
‘(◡𝐹‘𝐴)))) |
| 32 | 25, 31 | mtbird 674 |
. . . . . . . 8
⊢ (𝐴 ∈ ℕ → ¬ 2
∥ ((1st ‘(◡𝐹‘𝐴)) · (1st ‘(◡𝐹‘𝐴)))) |
| 33 | 22 | nncnd 9004 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℕ →
(1st ‘(◡𝐹‘𝐴)) ∈ ℂ) |
| 34 | 33 | sqvald 10762 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℕ →
((1st ‘(◡𝐹‘𝐴))↑2) = ((1st ‘(◡𝐹‘𝐴)) · (1st ‘(◡𝐹‘𝐴)))) |
| 35 | 34 | breq2d 4045 |
. . . . . . . 8
⊢ (𝐴 ∈ ℕ → (2
∥ ((1st ‘(◡𝐹‘𝐴))↑2) ↔ 2 ∥ ((1st
‘(◡𝐹‘𝐴)) · (1st ‘(◡𝐹‘𝐴))))) |
| 36 | 32, 35 | mtbird 674 |
. . . . . . 7
⊢ (𝐴 ∈ ℕ → ¬ 2
∥ ((1st ‘(◡𝐹‘𝐴))↑2)) |
| 37 | | breq2 4037 |
. . . . . . . . 9
⊢ (𝑧 = ((1st
‘(◡𝐹‘𝐴))↑2) → (2 ∥ 𝑧 ↔ 2 ∥
((1st ‘(◡𝐹‘𝐴))↑2))) |
| 38 | 37 | notbid 668 |
. . . . . . . 8
⊢ (𝑧 = ((1st
‘(◡𝐹‘𝐴))↑2) → (¬ 2 ∥ 𝑧 ↔ ¬ 2 ∥
((1st ‘(◡𝐹‘𝐴))↑2))) |
| 39 | 38, 1 | elrab2 2923 |
. . . . . . 7
⊢
(((1st ‘(◡𝐹‘𝐴))↑2) ∈ 𝐽 ↔ (((1st ‘(◡𝐹‘𝐴))↑2) ∈ ℕ ∧ ¬ 2
∥ ((1st ‘(◡𝐹‘𝐴))↑2))) |
| 40 | 23, 36, 39 | sylanbrc 417 |
. . . . . 6
⊢ (𝐴 ∈ ℕ →
((1st ‘(◡𝐹‘𝐴))↑2) ∈ 𝐽) |
| 41 | 12 | nnnn0d 9302 |
. . . . . . 7
⊢ (𝐴 ∈ ℕ → 2 ∈
ℕ0) |
| 42 | 9, 41 | nn0mulcld 9307 |
. . . . . 6
⊢ (𝐴 ∈ ℕ →
((2nd ‘(◡𝐹‘𝐴)) · 2) ∈
ℕ0) |
| 43 | | opelxp 4693 |
. . . . . 6
⊢
(〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉 ∈ (𝐽 × ℕ0)
↔ (((1st ‘(◡𝐹‘𝐴))↑2) ∈ 𝐽 ∧ ((2nd ‘(◡𝐹‘𝐴)) · 2) ∈
ℕ0)) |
| 44 | 40, 42, 43 | sylanbrc 417 |
. . . . 5
⊢ (𝐴 ∈ ℕ →
〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉 ∈ (𝐽 ×
ℕ0)) |
| 45 | 12 | nncnd 9004 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℕ → 2 ∈
ℂ) |
| 46 | 45, 41, 9 | expmuld 10768 |
. . . . . . . 8
⊢ (𝐴 ∈ ℕ →
(2↑((2nd ‘(◡𝐹‘𝐴)) · 2)) = ((2↑(2nd
‘(◡𝐹‘𝐴)))↑2)) |
| 47 | 46 | oveq1d 5937 |
. . . . . . 7
⊢ (𝐴 ∈ ℕ →
((2↑((2nd ‘(◡𝐹‘𝐴)) · 2)) · ((1st
‘(◡𝐹‘𝐴))↑2)) = (((2↑(2nd
‘(◡𝐹‘𝐴)))↑2) · ((1st
‘(◡𝐹‘𝐴))↑2))) |
| 48 | 12, 42 | nnexpcld 10787 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℕ →
(2↑((2nd ‘(◡𝐹‘𝐴)) · 2)) ∈
ℕ) |
| 49 | 48, 23 | nnmulcld 9039 |
. . . . . . . 8
⊢ (𝐴 ∈ ℕ →
((2↑((2nd ‘(◡𝐹‘𝐴)) · 2)) · ((1st
‘(◡𝐹‘𝐴))↑2)) ∈ ℕ) |
| 50 | | oveq2 5930 |
. . . . . . . . 9
⊢ (𝑥 = ((1st
‘(◡𝐹‘𝐴))↑2) → ((2↑𝑦) · 𝑥) = ((2↑𝑦) · ((1st ‘(◡𝐹‘𝐴))↑2))) |
| 51 | | oveq2 5930 |
. . . . . . . . . 10
⊢ (𝑦 = ((2nd
‘(◡𝐹‘𝐴)) · 2) → (2↑𝑦) = (2↑((2nd
‘(◡𝐹‘𝐴)) · 2))) |
| 52 | 51 | oveq1d 5937 |
. . . . . . . . 9
⊢ (𝑦 = ((2nd
‘(◡𝐹‘𝐴)) · 2) → ((2↑𝑦) · ((1st
‘(◡𝐹‘𝐴))↑2)) = ((2↑((2nd
‘(◡𝐹‘𝐴)) · 2)) · ((1st
‘(◡𝐹‘𝐴))↑2))) |
| 53 | 50, 52, 2 | ovmpog 6057 |
. . . . . . . 8
⊢
((((1st ‘(◡𝐹‘𝐴))↑2) ∈ 𝐽 ∧ ((2nd ‘(◡𝐹‘𝐴)) · 2) ∈ ℕ0
∧ ((2↑((2nd ‘(◡𝐹‘𝐴)) · 2)) · ((1st
‘(◡𝐹‘𝐴))↑2)) ∈ ℕ) →
(((1st ‘(◡𝐹‘𝐴))↑2)𝐹((2nd ‘(◡𝐹‘𝐴)) · 2)) = ((2↑((2nd
‘(◡𝐹‘𝐴)) · 2)) · ((1st
‘(◡𝐹‘𝐴))↑2))) |
| 54 | 40, 42, 49, 53 | syl3anc 1249 |
. . . . . . 7
⊢ (𝐴 ∈ ℕ →
(((1st ‘(◡𝐹‘𝐴))↑2)𝐹((2nd ‘(◡𝐹‘𝐴)) · 2)) = ((2↑((2nd
‘(◡𝐹‘𝐴)) · 2)) · ((1st
‘(◡𝐹‘𝐴))↑2))) |
| 55 | | f1ocnvfv2 5825 |
. . . . . . . . . . . . 13
⊢ ((𝐹:(𝐽 × ℕ0)–1-1-onto→ℕ ∧ 𝐴 ∈ ℕ) → (𝐹‘(◡𝐹‘𝐴)) = 𝐴) |
| 56 | 3, 55 | mpan 424 |
. . . . . . . . . . . 12
⊢ (𝐴 ∈ ℕ → (𝐹‘(◡𝐹‘𝐴)) = 𝐴) |
| 57 | | 1st2nd2 6233 |
. . . . . . . . . . . . . 14
⊢ ((◡𝐹‘𝐴) ∈ (𝐽 × ℕ0) → (◡𝐹‘𝐴) = 〈(1st ‘(◡𝐹‘𝐴)), (2nd ‘(◡𝐹‘𝐴))〉) |
| 58 | 7, 57 | syl 14 |
. . . . . . . . . . . . 13
⊢ (𝐴 ∈ ℕ → (◡𝐹‘𝐴) = 〈(1st ‘(◡𝐹‘𝐴)), (2nd ‘(◡𝐹‘𝐴))〉) |
| 59 | 58 | fveq2d 5562 |
. . . . . . . . . . . 12
⊢ (𝐴 ∈ ℕ → (𝐹‘(◡𝐹‘𝐴)) = (𝐹‘〈(1st ‘(◡𝐹‘𝐴)), (2nd ‘(◡𝐹‘𝐴))〉)) |
| 60 | 56, 59 | eqtr3d 2231 |
. . . . . . . . . . 11
⊢ (𝐴 ∈ ℕ → 𝐴 = (𝐹‘〈(1st ‘(◡𝐹‘𝐴)), (2nd ‘(◡𝐹‘𝐴))〉)) |
| 61 | | df-ov 5925 |
. . . . . . . . . . 11
⊢
((1st ‘(◡𝐹‘𝐴))𝐹(2nd ‘(◡𝐹‘𝐴))) = (𝐹‘〈(1st ‘(◡𝐹‘𝐴)), (2nd ‘(◡𝐹‘𝐴))〉) |
| 62 | 60, 61 | eqtr4di 2247 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℕ → 𝐴 = ((1st
‘(◡𝐹‘𝐴))𝐹(2nd ‘(◡𝐹‘𝐴)))) |
| 63 | 12, 9 | nnexpcld 10787 |
. . . . . . . . . . . 12
⊢ (𝐴 ∈ ℕ →
(2↑(2nd ‘(◡𝐹‘𝐴))) ∈ ℕ) |
| 64 | 63, 22 | nnmulcld 9039 |
. . . . . . . . . . 11
⊢ (𝐴 ∈ ℕ →
((2↑(2nd ‘(◡𝐹‘𝐴))) · (1st ‘(◡𝐹‘𝐴))) ∈ ℕ) |
| 65 | | oveq2 5930 |
. . . . . . . . . . . 12
⊢ (𝑥 = (1st ‘(◡𝐹‘𝐴)) → ((2↑𝑦) · 𝑥) = ((2↑𝑦) · (1st ‘(◡𝐹‘𝐴)))) |
| 66 | | oveq2 5930 |
. . . . . . . . . . . . 13
⊢ (𝑦 = (2nd ‘(◡𝐹‘𝐴)) → (2↑𝑦) = (2↑(2nd ‘(◡𝐹‘𝐴)))) |
| 67 | 66 | oveq1d 5937 |
. . . . . . . . . . . 12
⊢ (𝑦 = (2nd ‘(◡𝐹‘𝐴)) → ((2↑𝑦) · (1st ‘(◡𝐹‘𝐴))) = ((2↑(2nd ‘(◡𝐹‘𝐴))) · (1st ‘(◡𝐹‘𝐴)))) |
| 68 | 65, 67, 2 | ovmpog 6057 |
. . . . . . . . . . 11
⊢
(((1st ‘(◡𝐹‘𝐴)) ∈ 𝐽 ∧ (2nd ‘(◡𝐹‘𝐴)) ∈ ℕ0 ∧
((2↑(2nd ‘(◡𝐹‘𝐴))) · (1st ‘(◡𝐹‘𝐴))) ∈ ℕ) → ((1st
‘(◡𝐹‘𝐴))𝐹(2nd ‘(◡𝐹‘𝐴))) = ((2↑(2nd ‘(◡𝐹‘𝐴))) · (1st ‘(◡𝐹‘𝐴)))) |
| 69 | 17, 9, 64, 68 | syl3anc 1249 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℕ →
((1st ‘(◡𝐹‘𝐴))𝐹(2nd ‘(◡𝐹‘𝐴))) = ((2↑(2nd ‘(◡𝐹‘𝐴))) · (1st ‘(◡𝐹‘𝐴)))) |
| 70 | 62, 69 | eqtrd 2229 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℕ → 𝐴 = ((2↑(2nd
‘(◡𝐹‘𝐴))) · (1st ‘(◡𝐹‘𝐴)))) |
| 71 | 70 | oveq1d 5937 |
. . . . . . . 8
⊢ (𝐴 ∈ ℕ → (𝐴↑2) =
(((2↑(2nd ‘(◡𝐹‘𝐴))) · (1st ‘(◡𝐹‘𝐴)))↑2)) |
| 72 | 63 | nncnd 9004 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℕ →
(2↑(2nd ‘(◡𝐹‘𝐴))) ∈ ℂ) |
| 73 | 72, 33 | sqmuld 10777 |
. . . . . . . 8
⊢ (𝐴 ∈ ℕ →
(((2↑(2nd ‘(◡𝐹‘𝐴))) · (1st ‘(◡𝐹‘𝐴)))↑2) = (((2↑(2nd
‘(◡𝐹‘𝐴)))↑2) · ((1st
‘(◡𝐹‘𝐴))↑2))) |
| 74 | 71, 73 | eqtrd 2229 |
. . . . . . 7
⊢ (𝐴 ∈ ℕ → (𝐴↑2) =
(((2↑(2nd ‘(◡𝐹‘𝐴)))↑2) · ((1st
‘(◡𝐹‘𝐴))↑2))) |
| 75 | 47, 54, 74 | 3eqtr4rd 2240 |
. . . . . 6
⊢ (𝐴 ∈ ℕ → (𝐴↑2) = (((1st
‘(◡𝐹‘𝐴))↑2)𝐹((2nd ‘(◡𝐹‘𝐴)) · 2))) |
| 76 | | df-ov 5925 |
. . . . . 6
⊢
(((1st ‘(◡𝐹‘𝐴))↑2)𝐹((2nd ‘(◡𝐹‘𝐴)) · 2)) = (𝐹‘〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉) |
| 77 | 75, 76 | eqtr2di 2246 |
. . . . 5
⊢ (𝐴 ∈ ℕ → (𝐹‘〈((1st
‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉) = (𝐴↑2)) |
| 78 | | f1ocnvfv 5826 |
. . . . . 6
⊢ ((𝐹:(𝐽 × ℕ0)–1-1-onto→ℕ ∧ 〈((1st
‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉 ∈ (𝐽 × ℕ0))
→ ((𝐹‘〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉) = (𝐴↑2) → (◡𝐹‘(𝐴↑2)) = 〈((1st
‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉)) |
| 79 | 3, 78 | mpan 424 |
. . . . 5
⊢
(〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉 ∈ (𝐽 × ℕ0)
→ ((𝐹‘〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉) = (𝐴↑2) → (◡𝐹‘(𝐴↑2)) = 〈((1st
‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉)) |
| 80 | 44, 77, 79 | sylc 62 |
. . . 4
⊢ (𝐴 ∈ ℕ → (◡𝐹‘(𝐴↑2)) = 〈((1st
‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉) |
| 81 | 80 | fveq2d 5562 |
. . 3
⊢ (𝐴 ∈ ℕ →
(2nd ‘(◡𝐹‘(𝐴↑2))) = (2nd
‘〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉)) |
| 82 | | op2ndg 6209 |
. . . 4
⊢
((((1st ‘(◡𝐹‘𝐴))↑2) ∈ 𝐽 ∧ ((2nd ‘(◡𝐹‘𝐴)) · 2) ∈ ℕ0)
→ (2nd ‘〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉) = ((2nd
‘(◡𝐹‘𝐴)) · 2)) |
| 83 | 40, 42, 82 | syl2anc 411 |
. . 3
⊢ (𝐴 ∈ ℕ →
(2nd ‘〈((1st ‘(◡𝐹‘𝐴))↑2), ((2nd ‘(◡𝐹‘𝐴)) · 2)〉) = ((2nd
‘(◡𝐹‘𝐴)) · 2)) |
| 84 | 81, 83 | eqtrd 2229 |
. 2
⊢ (𝐴 ∈ ℕ →
(2nd ‘(◡𝐹‘(𝐴↑2))) = ((2nd ‘(◡𝐹‘𝐴)) · 2)) |
| 85 | 15, 84 | breqtrrd 4061 |
1
⊢ (𝐴 ∈ ℕ → 2 ∥
(2nd ‘(◡𝐹‘(𝐴↑2)))) |