| Step | Hyp | Ref
 | Expression | 
| 1 |   | fprodss.1 | 
. . 3
⊢ (𝜑 → 𝐴 ⊆ 𝐵) | 
| 2 |   | sseq2 3207 | 
. . . . 5
⊢ (𝐵 = ∅ → (𝐴 ⊆ 𝐵 ↔ 𝐴 ⊆ ∅)) | 
| 3 |   | ss0 3491 | 
. . . . 5
⊢ (𝐴 ⊆ ∅ → 𝐴 = ∅) | 
| 4 | 2, 3 | biimtrdi 163 | 
. . . 4
⊢ (𝐵 = ∅ → (𝐴 ⊆ 𝐵 → 𝐴 = ∅)) | 
| 5 |   | prodeq1 11718 | 
. . . . . 6
⊢ (𝐴 = ∅ → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ ∅ 𝐶) | 
| 6 |   | prodeq1 11718 | 
. . . . . . 7
⊢ (𝐵 = ∅ → ∏𝑘 ∈ 𝐵 𝐶 = ∏𝑘 ∈ ∅ 𝐶) | 
| 7 | 6 | eqcomd 2202 | 
. . . . . 6
⊢ (𝐵 = ∅ → ∏𝑘 ∈ ∅ 𝐶 = ∏𝑘 ∈ 𝐵 𝐶) | 
| 8 | 5, 7 | sylan9eq 2249 | 
. . . . 5
⊢ ((𝐴 = ∅ ∧ 𝐵 = ∅) → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶) | 
| 9 | 8 | expcom 116 | 
. . . 4
⊢ (𝐵 = ∅ → (𝐴 = ∅ → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶)) | 
| 10 | 4, 9 | syld 45 | 
. . 3
⊢ (𝐵 = ∅ → (𝐴 ⊆ 𝐵 → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶)) | 
| 11 | 1, 10 | syl5com 29 | 
. 2
⊢ (𝜑 → (𝐵 = ∅ → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶)) | 
| 12 |   | cnvimass 5032 | 
. . . . . . . . 9
⊢ (◡𝑓 “ 𝐴) ⊆ dom 𝑓 | 
| 13 |   | simprr 531 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵) | 
| 14 |   | f1of 5504 | 
. . . . . . . . . 10
⊢ (𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵 → 𝑓:(1...(♯‘𝐵))⟶𝐵) | 
| 15 | 13, 14 | syl 14 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → 𝑓:(1...(♯‘𝐵))⟶𝐵) | 
| 16 | 12, 15 | fssdm 5422 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (◡𝑓 “ 𝐴) ⊆ (1...(♯‘𝐵))) | 
| 17 |   | f1ofn 5505 | 
. . . . . . . . . . . 12
⊢ (𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵 → 𝑓 Fn (1...(♯‘𝐵))) | 
| 18 |   | elpreima 5681 | 
. . . . . . . . . . . 12
⊢ (𝑓 Fn (1...(♯‘𝐵)) → (𝑛 ∈ (◡𝑓 “ 𝐴) ↔ (𝑛 ∈ (1...(♯‘𝐵)) ∧ (𝑓‘𝑛) ∈ 𝐴))) | 
| 19 | 13, 17, 18 | 3syl 17 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (𝑛 ∈ (◡𝑓 “ 𝐴) ↔ (𝑛 ∈ (1...(♯‘𝐵)) ∧ (𝑓‘𝑛) ∈ 𝐴))) | 
| 20 | 15 | ffvelcdmda 5697 | 
. . . . . . . . . . . . 13
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ (1...(♯‘𝐵))) → (𝑓‘𝑛) ∈ 𝐵) | 
| 21 | 20 | ex 115 | 
. . . . . . . . . . . 12
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (𝑛 ∈ (1...(♯‘𝐵)) → (𝑓‘𝑛) ∈ 𝐵)) | 
| 22 | 21 | adantrd 279 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ((𝑛 ∈ (1...(♯‘𝐵)) ∧ (𝑓‘𝑛) ∈ 𝐴) → (𝑓‘𝑛) ∈ 𝐵)) | 
| 23 | 19, 22 | sylbid 150 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (𝑛 ∈ (◡𝑓 “ 𝐴) → (𝑓‘𝑛) ∈ 𝐵)) | 
| 24 | 23 | imp 124 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ (◡𝑓 “ 𝐴)) → (𝑓‘𝑛) ∈ 𝐵) | 
| 25 |   | fprodss.2 | 
. . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐶 ∈ ℂ) | 
| 26 | 25 | ex 115 | 
. . . . . . . . . . . . . 14
⊢ (𝜑 → (𝑘 ∈ 𝐴 → 𝐶 ∈ ℂ)) | 
| 27 | 26 | adantr 276 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐵) → (𝑘 ∈ 𝐴 → 𝐶 ∈ ℂ)) | 
| 28 |   | eldif 3166 | 
. . . . . . . . . . . . . . 15
⊢ (𝑘 ∈ (𝐵 ∖ 𝐴) ↔ (𝑘 ∈ 𝐵 ∧ ¬ 𝑘 ∈ 𝐴)) | 
| 29 |   | fprodss.3 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝜑 ∧ 𝑘 ∈ (𝐵 ∖ 𝐴)) → 𝐶 = 1) | 
| 30 |   | ax-1cn 7972 | 
. . . . . . . . . . . . . . . 16
⊢ 1 ∈
ℂ | 
| 31 | 29, 30 | eqeltrdi 2287 | 
. . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ 𝑘 ∈ (𝐵 ∖ 𝐴)) → 𝐶 ∈ ℂ) | 
| 32 | 28, 31 | sylan2br 288 | 
. . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ (𝑘 ∈ 𝐵 ∧ ¬ 𝑘 ∈ 𝐴)) → 𝐶 ∈ ℂ) | 
| 33 | 32 | expr 375 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐵) → (¬ 𝑘 ∈ 𝐴 → 𝐶 ∈ ℂ)) | 
| 34 |   | eleq1 2259 | 
. . . . . . . . . . . . . . . 16
⊢ (𝑗 = 𝑘 → (𝑗 ∈ 𝐴 ↔ 𝑘 ∈ 𝐴)) | 
| 35 | 34 | dcbid 839 | 
. . . . . . . . . . . . . . 15
⊢ (𝑗 = 𝑘 → (DECID 𝑗 ∈ 𝐴 ↔ DECID 𝑘 ∈ 𝐴)) | 
| 36 |   | fprodssdc.a | 
. . . . . . . . . . . . . . . 16
⊢ (𝜑 → ∀𝑗 ∈ 𝐵 DECID 𝑗 ∈ 𝐴) | 
| 37 | 36 | adantr 276 | 
. . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐵) → ∀𝑗 ∈ 𝐵 DECID 𝑗 ∈ 𝐴) | 
| 38 |   | simpr 110 | 
. . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐵) → 𝑘 ∈ 𝐵) | 
| 39 | 35, 37, 38 | rspcdva 2873 | 
. . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐵) → DECID 𝑘 ∈ 𝐴) | 
| 40 |   | exmiddc 837 | 
. . . . . . . . . . . . . 14
⊢
(DECID 𝑘 ∈ 𝐴 → (𝑘 ∈ 𝐴 ∨ ¬ 𝑘 ∈ 𝐴)) | 
| 41 | 39, 40 | syl 14 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐵) → (𝑘 ∈ 𝐴 ∨ ¬ 𝑘 ∈ 𝐴)) | 
| 42 | 27, 33, 41 | mpjaod 719 | 
. . . . . . . . . . . 12
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐵) → 𝐶 ∈ ℂ) | 
| 43 | 42 | adantlr 477 | 
. . . . . . . . . . 11
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑘 ∈ 𝐵) → 𝐶 ∈ ℂ) | 
| 44 | 43 | fmpttd 5717 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (𝑘 ∈ 𝐵 ↦ 𝐶):𝐵⟶ℂ) | 
| 45 | 44 | ffvelcdmda 5697 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ (𝑓‘𝑛) ∈ 𝐵) → ((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛)) ∈ ℂ) | 
| 46 | 24, 45 | syldan 282 | 
. . . . . . . 8
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ (◡𝑓 “ 𝐴)) → ((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛)) ∈ ℂ) | 
| 47 |   | eqid 2196 | 
. . . . . . . . 9
⊢
(ℤ≥‘1) =
(ℤ≥‘1) | 
| 48 |   | simprl 529 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (♯‘𝐵) ∈
ℕ) | 
| 49 |   | nnuz 9637 | 
. . . . . . . . . 10
⊢ ℕ =
(ℤ≥‘1) | 
| 50 | 48, 49 | eleqtrdi 2289 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (♯‘𝐵) ∈
(ℤ≥‘1)) | 
| 51 |   | ssidd 3204 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) →
(1...(♯‘𝐵))
⊆ (1...(♯‘𝐵))) | 
| 52 | 47, 50, 51 | fprodntrivap 11749 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∃𝑚 ∈
(ℤ≥‘1)∃𝑦(𝑦 # 0 ∧ seq𝑚( · , (𝑛 ∈ (ℤ≥‘1)
↦ if(𝑛 ∈
(1...(♯‘𝐵)),
((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛)), 1))) ⇝ 𝑦)) | 
| 53 |   | eleq1 2259 | 
. . . . . . . . . . . . 13
⊢ (𝑗 = (𝑓‘𝑝) → (𝑗 ∈ 𝐴 ↔ (𝑓‘𝑝) ∈ 𝐴)) | 
| 54 | 53 | dcbid 839 | 
. . . . . . . . . . . 12
⊢ (𝑗 = (𝑓‘𝑝) → (DECID 𝑗 ∈ 𝐴 ↔ DECID (𝑓‘𝑝) ∈ 𝐴)) | 
| 55 | 36 | ad3antrrr 492 | 
. . . . . . . . . . . 12
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ ∀𝑗 ∈
𝐵 DECID
𝑗 ∈ 𝐴) | 
| 56 | 13 | ad2antrr 488 | 
. . . . . . . . . . . . . 14
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵) | 
| 57 | 56, 14 | syl 14 | 
. . . . . . . . . . . . 13
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ 𝑓:(1...(♯‘𝐵))⟶𝐵) | 
| 58 |   | simpr 110 | 
. . . . . . . . . . . . 13
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ 𝑝 ∈
(1...(♯‘𝐵))) | 
| 59 | 57, 58 | ffvelcdmd 5698 | 
. . . . . . . . . . . 12
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ (𝑓‘𝑝) ∈ 𝐵) | 
| 60 | 54, 55, 59 | rspcdva 2873 | 
. . . . . . . . . . 11
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ DECID (𝑓‘𝑝) ∈ 𝐴) | 
| 61 |   | f1ocnv 5517 | 
. . . . . . . . . . . . . . 15
⊢ (𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵 → ◡𝑓:𝐵–1-1-onto→(1...(♯‘𝐵))) | 
| 62 |   | f1of1 5503 | 
. . . . . . . . . . . . . . 15
⊢ (◡𝑓:𝐵–1-1-onto→(1...(♯‘𝐵)) → ◡𝑓:𝐵–1-1→(1...(♯‘𝐵))) | 
| 63 | 56, 61, 62 | 3syl 17 | 
. . . . . . . . . . . . . 14
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ ◡𝑓:𝐵–1-1→(1...(♯‘𝐵))) | 
| 64 | 1 | ad3antrrr 492 | 
. . . . . . . . . . . . . 14
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ 𝐴 ⊆ 𝐵) | 
| 65 |   | f1elima 5820 | 
. . . . . . . . . . . . . 14
⊢ ((◡𝑓:𝐵–1-1→(1...(♯‘𝐵)) ∧ (𝑓‘𝑝) ∈ 𝐵 ∧ 𝐴 ⊆ 𝐵) → ((◡𝑓‘(𝑓‘𝑝)) ∈ (◡𝑓 “ 𝐴) ↔ (𝑓‘𝑝) ∈ 𝐴)) | 
| 66 | 63, 59, 64, 65 | syl3anc 1249 | 
. . . . . . . . . . . . 13
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ ((◡𝑓‘(𝑓‘𝑝)) ∈ (◡𝑓 “ 𝐴) ↔ (𝑓‘𝑝) ∈ 𝐴)) | 
| 67 |   | f1ocnvfv1 5824 | 
. . . . . . . . . . . . . . 15
⊢ ((𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵 ∧ 𝑝 ∈ (1...(♯‘𝐵))) → (◡𝑓‘(𝑓‘𝑝)) = 𝑝) | 
| 68 | 56, 58, 67 | syl2anc 411 | 
. . . . . . . . . . . . . 14
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ (◡𝑓‘(𝑓‘𝑝)) = 𝑝) | 
| 69 | 68 | eleq1d 2265 | 
. . . . . . . . . . . . 13
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ ((◡𝑓‘(𝑓‘𝑝)) ∈ (◡𝑓 “ 𝐴) ↔ 𝑝 ∈ (◡𝑓 “ 𝐴))) | 
| 70 | 66, 69 | bitr3d 190 | 
. . . . . . . . . . . 12
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ ((𝑓‘𝑝) ∈ 𝐴 ↔ 𝑝 ∈ (◡𝑓 “ 𝐴))) | 
| 71 | 70 | dcbid 839 | 
. . . . . . . . . . 11
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ (DECID (𝑓‘𝑝) ∈ 𝐴 ↔ DECID 𝑝 ∈ (◡𝑓 “ 𝐴))) | 
| 72 | 60, 71 | mpbid 147 | 
. . . . . . . . . 10
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ 𝑝 ∈
(1...(♯‘𝐵)))
→ DECID 𝑝 ∈ (◡𝑓 “ 𝐴)) | 
| 73 | 16 | ad2antrr 488 | 
. . . . . . . . . . . . 13
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ ¬ 𝑝 ∈
(1...(♯‘𝐵)))
→ (◡𝑓 “ 𝐴) ⊆ (1...(♯‘𝐵))) | 
| 74 |   | simpr 110 | 
. . . . . . . . . . . . 13
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ ¬ 𝑝 ∈
(1...(♯‘𝐵)))
→ ¬ 𝑝 ∈
(1...(♯‘𝐵))) | 
| 75 | 73, 74 | ssneldd 3186 | 
. . . . . . . . . . . 12
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ ¬ 𝑝 ∈
(1...(♯‘𝐵)))
→ ¬ 𝑝 ∈
(◡𝑓 “ 𝐴)) | 
| 76 | 75 | olcd 735 | 
. . . . . . . . . . 11
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ ¬ 𝑝 ∈
(1...(♯‘𝐵)))
→ (𝑝 ∈ (◡𝑓 “ 𝐴) ∨ ¬ 𝑝 ∈ (◡𝑓 “ 𝐴))) | 
| 77 |   | df-dc 836 | 
. . . . . . . . . . 11
⊢
(DECID 𝑝 ∈ (◡𝑓 “ 𝐴) ↔ (𝑝 ∈ (◡𝑓 “ 𝐴) ∨ ¬ 𝑝 ∈ (◡𝑓 “ 𝐴))) | 
| 78 | 76, 77 | sylibr 134 | 
. . . . . . . . . 10
⊢ ((((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
∧ ¬ 𝑝 ∈
(1...(♯‘𝐵)))
→ DECID 𝑝 ∈ (◡𝑓 “ 𝐴)) | 
| 79 |   | eluzelz 9610 | 
. . . . . . . . . . . . 13
⊢ (𝑝 ∈
(ℤ≥‘1) → 𝑝 ∈ ℤ) | 
| 80 | 79 | adantl 277 | 
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
→ 𝑝 ∈
ℤ) | 
| 81 |   | 1zzd 9353 | 
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
→ 1 ∈ ℤ) | 
| 82 | 48 | adantr 276 | 
. . . . . . . . . . . . 13
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
→ (♯‘𝐵)
∈ ℕ) | 
| 83 | 82 | nnzd 9447 | 
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
→ (♯‘𝐵)
∈ ℤ) | 
| 84 |   | fzdcel 10115 | 
. . . . . . . . . . . 12
⊢ ((𝑝 ∈ ℤ ∧ 1 ∈
ℤ ∧ (♯‘𝐵) ∈ ℤ) →
DECID 𝑝
∈ (1...(♯‘𝐵))) | 
| 85 | 80, 81, 83, 84 | syl3anc 1249 | 
. . . . . . . . . . 11
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
→ DECID 𝑝 ∈ (1...(♯‘𝐵))) | 
| 86 |   | exmiddc 837 | 
. . . . . . . . . . 11
⊢
(DECID 𝑝 ∈ (1...(♯‘𝐵)) → (𝑝 ∈ (1...(♯‘𝐵)) ∨ ¬ 𝑝 ∈ (1...(♯‘𝐵)))) | 
| 87 | 85, 86 | syl 14 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
→ (𝑝 ∈
(1...(♯‘𝐵))
∨ ¬ 𝑝 ∈
(1...(♯‘𝐵)))) | 
| 88 | 72, 78, 87 | mpjaodan 799 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑝 ∈ (ℤ≥‘1))
→ DECID 𝑝 ∈ (◡𝑓 “ 𝐴)) | 
| 89 | 88 | ralrimiva 2570 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∀𝑝 ∈
(ℤ≥‘1)DECID 𝑝 ∈ (◡𝑓 “ 𝐴)) | 
| 90 |   | 1zzd 9353 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → 1 ∈
ℤ) | 
| 91 |   | eldifi 3285 | 
. . . . . . . . . . . 12
⊢ (𝑛 ∈
((1...(♯‘𝐵))
∖ (◡𝑓 “ 𝐴)) → 𝑛 ∈ (1...(♯‘𝐵))) | 
| 92 | 91, 20 | sylan2 286 | 
. . . . . . . . . . 11
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → (𝑓‘𝑛) ∈ 𝐵) | 
| 93 |   | eldifn 3286 | 
. . . . . . . . . . . . 13
⊢ (𝑛 ∈
((1...(♯‘𝐵))
∖ (◡𝑓 “ 𝐴)) → ¬ 𝑛 ∈ (◡𝑓 “ 𝐴)) | 
| 94 | 93 | adantl 277 | 
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → ¬ 𝑛 ∈ (◡𝑓 “ 𝐴)) | 
| 95 | 91 | adantl 277 | 
. . . . . . . . . . . . 13
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → 𝑛 ∈ (1...(♯‘𝐵))) | 
| 96 | 19 | adantr 276 | 
. . . . . . . . . . . . 13
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → (𝑛 ∈ (◡𝑓 “ 𝐴) ↔ (𝑛 ∈ (1...(♯‘𝐵)) ∧ (𝑓‘𝑛) ∈ 𝐴))) | 
| 97 | 95, 96 | mpbirand 441 | 
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → (𝑛 ∈ (◡𝑓 “ 𝐴) ↔ (𝑓‘𝑛) ∈ 𝐴)) | 
| 98 | 94, 97 | mtbid 673 | 
. . . . . . . . . . 11
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → ¬ (𝑓‘𝑛) ∈ 𝐴) | 
| 99 | 92, 98 | eldifd 3167 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → (𝑓‘𝑛) ∈ (𝐵 ∖ 𝐴)) | 
| 100 |   | difss 3289 | 
. . . . . . . . . . . . 13
⊢ (𝐵 ∖ 𝐴) ⊆ 𝐵 | 
| 101 |   | resmpt 4994 | 
. . . . . . . . . . . . 13
⊢ ((𝐵 ∖ 𝐴) ⊆ 𝐵 → ((𝑘 ∈ 𝐵 ↦ 𝐶) ↾ (𝐵 ∖ 𝐴)) = (𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶)) | 
| 102 | 100, 101 | ax-mp 5 | 
. . . . . . . . . . . 12
⊢ ((𝑘 ∈ 𝐵 ↦ 𝐶) ↾ (𝐵 ∖ 𝐴)) = (𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶) | 
| 103 | 102 | fveq1i 5559 | 
. . . . . . . . . . 11
⊢ (((𝑘 ∈ 𝐵 ↦ 𝐶) ↾ (𝐵 ∖ 𝐴))‘(𝑓‘𝑛)) = ((𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶)‘(𝑓‘𝑛)) | 
| 104 |   | fvres 5582 | 
. . . . . . . . . . 11
⊢ ((𝑓‘𝑛) ∈ (𝐵 ∖ 𝐴) → (((𝑘 ∈ 𝐵 ↦ 𝐶) ↾ (𝐵 ∖ 𝐴))‘(𝑓‘𝑛)) = ((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛))) | 
| 105 | 103, 104 | eqtr3id 2243 | 
. . . . . . . . . 10
⊢ ((𝑓‘𝑛) ∈ (𝐵 ∖ 𝐴) → ((𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶)‘(𝑓‘𝑛)) = ((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛))) | 
| 106 | 99, 105 | syl 14 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → ((𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶)‘(𝑓‘𝑛)) = ((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛))) | 
| 107 |   | 1ex 8021 | 
. . . . . . . . . . . . . . 15
⊢ 1 ∈
V | 
| 108 | 107 | elsn2 3656 | 
. . . . . . . . . . . . . 14
⊢ (𝐶 ∈ {1} ↔ 𝐶 = 1) | 
| 109 | 29, 108 | sylibr 134 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ 𝑘 ∈ (𝐵 ∖ 𝐴)) → 𝐶 ∈ {1}) | 
| 110 | 109 | fmpttd 5717 | 
. . . . . . . . . . . 12
⊢ (𝜑 → (𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶):(𝐵 ∖ 𝐴)⟶{1}) | 
| 111 | 110 | ad2antrr 488 | 
. . . . . . . . . . 11
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → (𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶):(𝐵 ∖ 𝐴)⟶{1}) | 
| 112 | 111, 99 | ffvelcdmd 5698 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → ((𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶)‘(𝑓‘𝑛)) ∈ {1}) | 
| 113 |   | elsni 3640 | 
. . . . . . . . . 10
⊢ (((𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶)‘(𝑓‘𝑛)) ∈ {1} → ((𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶)‘(𝑓‘𝑛)) = 1) | 
| 114 | 112, 113 | syl 14 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → ((𝑘 ∈ (𝐵 ∖ 𝐴) ↦ 𝐶)‘(𝑓‘𝑛)) = 1) | 
| 115 | 106, 114 | eqtr3d 2231 | 
. . . . . . . 8
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ ((1...(♯‘𝐵)) ∖ (◡𝑓 “ 𝐴))) → ((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛)) = 1) | 
| 116 |   | fzssuz 10140 | 
. . . . . . . . 9
⊢
(1...(♯‘𝐵)) ⊆
(ℤ≥‘1) | 
| 117 | 116 | a1i 9 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) →
(1...(♯‘𝐵))
⊆ (ℤ≥‘1)) | 
| 118 | 85 | ralrimiva 2570 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∀𝑝 ∈
(ℤ≥‘1)DECID 𝑝 ∈ (1...(♯‘𝐵))) | 
| 119 | 16, 46, 52, 89, 90, 115, 117, 118 | prodssdc 11754 | 
. . . . . . 7
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑛 ∈ (◡𝑓 “ 𝐴)((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛)) = ∏𝑛 ∈ (1...(♯‘𝐵))((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛))) | 
| 120 | 1 | adantr 276 | 
. . . . . . . . . . . 12
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → 𝐴 ⊆ 𝐵) | 
| 121 | 120 | resmptd 4997 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ((𝑘 ∈ 𝐵 ↦ 𝐶) ↾ 𝐴) = (𝑘 ∈ 𝐴 ↦ 𝐶)) | 
| 122 | 121 | fveq1d 5560 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (((𝑘 ∈ 𝐵 ↦ 𝐶) ↾ 𝐴)‘𝑚) = ((𝑘 ∈ 𝐴 ↦ 𝐶)‘𝑚)) | 
| 123 |   | fvres 5582 | 
. . . . . . . . . 10
⊢ (𝑚 ∈ 𝐴 → (((𝑘 ∈ 𝐵 ↦ 𝐶) ↾ 𝐴)‘𝑚) = ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚)) | 
| 124 | 122, 123 | sylan9req 2250 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑚 ∈ 𝐴) → ((𝑘 ∈ 𝐴 ↦ 𝐶)‘𝑚) = ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚)) | 
| 125 | 124 | prodeq2dv 11731 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑚 ∈ 𝐴 ((𝑘 ∈ 𝐴 ↦ 𝐶)‘𝑚) = ∏𝑚 ∈ 𝐴 ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚)) | 
| 126 |   | fveq2 5558 | 
. . . . . . . . 9
⊢ (𝑚 = (𝑓‘𝑛) → ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚) = ((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛))) | 
| 127 |   | fprodss.4 | 
. . . . . . . . . . . 12
⊢ (𝜑 → 𝐵 ∈ Fin) | 
| 128 | 127 | adantr 276 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → 𝐵 ∈ Fin) | 
| 129 | 36 | adantr 276 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∀𝑗 ∈ 𝐵 DECID 𝑗 ∈ 𝐴) | 
| 130 |   | ssfidc 6998 | 
. . . . . . . . . . 11
⊢ ((𝐵 ∈ Fin ∧ 𝐴 ⊆ 𝐵 ∧ ∀𝑗 ∈ 𝐵 DECID 𝑗 ∈ 𝐴) → 𝐴 ∈ Fin) | 
| 131 | 128, 120,
129, 130 | syl3anc 1249 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → 𝐴 ∈ Fin) | 
| 132 | 120, 13, 131 | preimaf1ofi 7017 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (◡𝑓 “ 𝐴) ∈ Fin) | 
| 133 |   | f1of1 5503 | 
. . . . . . . . . . . 12
⊢ (𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵 → 𝑓:(1...(♯‘𝐵))–1-1→𝐵) | 
| 134 | 13, 133 | syl 14 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → 𝑓:(1...(♯‘𝐵))–1-1→𝐵) | 
| 135 |   | f1ores 5519 | 
. . . . . . . . . . 11
⊢ ((𝑓:(1...(♯‘𝐵))–1-1→𝐵 ∧ (◡𝑓 “ 𝐴) ⊆ (1...(♯‘𝐵))) → (𝑓 ↾ (◡𝑓 “ 𝐴)):(◡𝑓 “ 𝐴)–1-1-onto→(𝑓 “ (◡𝑓 “ 𝐴))) | 
| 136 | 134, 16, 135 | syl2anc 411 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (𝑓 ↾ (◡𝑓 “ 𝐴)):(◡𝑓 “ 𝐴)–1-1-onto→(𝑓 “ (◡𝑓 “ 𝐴))) | 
| 137 |   | f1ofo 5511 | 
. . . . . . . . . . . . 13
⊢ (𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵 → 𝑓:(1...(♯‘𝐵))–onto→𝐵) | 
| 138 | 13, 137 | syl 14 | 
. . . . . . . . . . . 12
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → 𝑓:(1...(♯‘𝐵))–onto→𝐵) | 
| 139 |   | foimacnv 5522 | 
. . . . . . . . . . . 12
⊢ ((𝑓:(1...(♯‘𝐵))–onto→𝐵 ∧ 𝐴 ⊆ 𝐵) → (𝑓 “ (◡𝑓 “ 𝐴)) = 𝐴) | 
| 140 | 138, 120,
139 | syl2anc 411 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (𝑓 “ (◡𝑓 “ 𝐴)) = 𝐴) | 
| 141 | 140 | f1oeq3d 5501 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ((𝑓 ↾ (◡𝑓 “ 𝐴)):(◡𝑓 “ 𝐴)–1-1-onto→(𝑓 “ (◡𝑓 “ 𝐴)) ↔ (𝑓 ↾ (◡𝑓 “ 𝐴)):(◡𝑓 “ 𝐴)–1-1-onto→𝐴)) | 
| 142 | 136, 141 | mpbid 147 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (𝑓 ↾ (◡𝑓 “ 𝐴)):(◡𝑓 “ 𝐴)–1-1-onto→𝐴) | 
| 143 |   | fvres 5582 | 
. . . . . . . . . 10
⊢ (𝑛 ∈ (◡𝑓 “ 𝐴) → ((𝑓 ↾ (◡𝑓 “ 𝐴))‘𝑛) = (𝑓‘𝑛)) | 
| 144 | 143 | adantl 277 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ (◡𝑓 “ 𝐴)) → ((𝑓 ↾ (◡𝑓 “ 𝐴))‘𝑛) = (𝑓‘𝑛)) | 
| 145 | 120 | sselda 3183 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑚 ∈ 𝐴) → 𝑚 ∈ 𝐵) | 
| 146 | 44 | ffvelcdmda 5697 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑚 ∈ 𝐵) → ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚) ∈ ℂ) | 
| 147 | 145, 146 | syldan 282 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑚 ∈ 𝐴) → ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚) ∈ ℂ) | 
| 148 | 126, 132,
142, 144, 147 | fprodf1o 11753 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑚 ∈ 𝐴 ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚) = ∏𝑛 ∈ (◡𝑓 “ 𝐴)((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛))) | 
| 149 | 125, 148 | eqtrd 2229 | 
. . . . . . 7
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑚 ∈ 𝐴 ((𝑘 ∈ 𝐴 ↦ 𝐶)‘𝑚) = ∏𝑛 ∈ (◡𝑓 “ 𝐴)((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛))) | 
| 150 | 48 | nnzd 9447 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → (♯‘𝐵) ∈
ℤ) | 
| 151 | 90, 150 | fzfigd 10523 | 
. . . . . . . 8
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) →
(1...(♯‘𝐵))
∈ Fin) | 
| 152 |   | eqidd 2197 | 
. . . . . . . 8
⊢ (((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) ∧ 𝑛 ∈ (1...(♯‘𝐵))) → (𝑓‘𝑛) = (𝑓‘𝑛)) | 
| 153 | 126, 151,
13, 152, 146 | fprodf1o 11753 | 
. . . . . . 7
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑚 ∈ 𝐵 ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚) = ∏𝑛 ∈ (1...(♯‘𝐵))((𝑘 ∈ 𝐵 ↦ 𝐶)‘(𝑓‘𝑛))) | 
| 154 | 119, 149,
153 | 3eqtr4d 2239 | 
. . . . . 6
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑚 ∈ 𝐴 ((𝑘 ∈ 𝐴 ↦ 𝐶)‘𝑚) = ∏𝑚 ∈ 𝐵 ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚)) | 
| 155 | 25 | ralrimiva 2570 | 
. . . . . . . 8
⊢ (𝜑 → ∀𝑘 ∈ 𝐴 𝐶 ∈ ℂ) | 
| 156 | 155 | adantr 276 | 
. . . . . . 7
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∀𝑘 ∈ 𝐴 𝐶 ∈ ℂ) | 
| 157 |   | prodfct 11752 | 
. . . . . . 7
⊢
(∀𝑘 ∈
𝐴 𝐶 ∈ ℂ → ∏𝑚 ∈ 𝐴 ((𝑘 ∈ 𝐴 ↦ 𝐶)‘𝑚) = ∏𝑘 ∈ 𝐴 𝐶) | 
| 158 | 156, 157 | syl 14 | 
. . . . . 6
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑚 ∈ 𝐴 ((𝑘 ∈ 𝐴 ↦ 𝐶)‘𝑚) = ∏𝑘 ∈ 𝐴 𝐶) | 
| 159 | 43 | ralrimiva 2570 | 
. . . . . . 7
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∀𝑘 ∈ 𝐵 𝐶 ∈ ℂ) | 
| 160 |   | prodfct 11752 | 
. . . . . . 7
⊢
(∀𝑘 ∈
𝐵 𝐶 ∈ ℂ → ∏𝑚 ∈ 𝐵 ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚) = ∏𝑘 ∈ 𝐵 𝐶) | 
| 161 | 159, 160 | syl 14 | 
. . . . . 6
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑚 ∈ 𝐵 ((𝑘 ∈ 𝐵 ↦ 𝐶)‘𝑚) = ∏𝑘 ∈ 𝐵 𝐶) | 
| 162 | 154, 158,
161 | 3eqtr3d 2237 | 
. . . . 5
⊢ ((𝜑 ∧ ((♯‘𝐵) ∈ ℕ ∧ 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵)) → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶) | 
| 163 | 162 | expr 375 | 
. . . 4
⊢ ((𝜑 ∧ (♯‘𝐵) ∈ ℕ) → (𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵 → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶)) | 
| 164 | 163 | exlimdv 1833 | 
. . 3
⊢ ((𝜑 ∧ (♯‘𝐵) ∈ ℕ) →
(∃𝑓 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵 → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶)) | 
| 165 | 164 | expimpd 363 | 
. 2
⊢ (𝜑 → (((♯‘𝐵) ∈ ℕ ∧
∃𝑓 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵) → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶)) | 
| 166 |   | fz1f1o 11540 | 
. . 3
⊢ (𝐵 ∈ Fin → (𝐵 = ∅ ∨
((♯‘𝐵) ∈
ℕ ∧ ∃𝑓
𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵))) | 
| 167 | 127, 166 | syl 14 | 
. 2
⊢ (𝜑 → (𝐵 = ∅ ∨ ((♯‘𝐵) ∈ ℕ ∧
∃𝑓 𝑓:(1...(♯‘𝐵))–1-1-onto→𝐵))) | 
| 168 | 11, 165, 167 | mpjaod 719 | 
1
⊢ (𝜑 → ∏𝑘 ∈ 𝐴 𝐶 = ∏𝑘 ∈ 𝐵 𝐶) |