| Step | Hyp | Ref
 | Expression | 
| 1 |   | prodeq1 11718 | 
. . 3
⊢ (𝑤 = ∅ → ∏𝑘 ∈ 𝑤 𝐵 = ∏𝑘 ∈ ∅ 𝐵) | 
| 2 | 1 | breq1d 4043 | 
. 2
⊢ (𝑤 = ∅ → (∏𝑘 ∈ 𝑤 𝐵 # 0 ↔ ∏𝑘 ∈ ∅ 𝐵 # 0)) | 
| 3 |   | prodeq1 11718 | 
. . 3
⊢ (𝑤 = 𝑦 → ∏𝑘 ∈ 𝑤 𝐵 = ∏𝑘 ∈ 𝑦 𝐵) | 
| 4 | 3 | breq1d 4043 | 
. 2
⊢ (𝑤 = 𝑦 → (∏𝑘 ∈ 𝑤 𝐵 # 0 ↔ ∏𝑘 ∈ 𝑦 𝐵 # 0)) | 
| 5 |   | prodeq1 11718 | 
. . 3
⊢ (𝑤 = (𝑦 ∪ {𝑧}) → ∏𝑘 ∈ 𝑤 𝐵 = ∏𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) | 
| 6 | 5 | breq1d 4043 | 
. 2
⊢ (𝑤 = (𝑦 ∪ {𝑧}) → (∏𝑘 ∈ 𝑤 𝐵 # 0 ↔ ∏𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 # 0)) | 
| 7 |   | prodeq1 11718 | 
. . 3
⊢ (𝑤 = 𝐴 → ∏𝑘 ∈ 𝑤 𝐵 = ∏𝑘 ∈ 𝐴 𝐵) | 
| 8 | 7 | breq1d 4043 | 
. 2
⊢ (𝑤 = 𝐴 → (∏𝑘 ∈ 𝑤 𝐵 # 0 ↔ ∏𝑘 ∈ 𝐴 𝐵 # 0)) | 
| 9 |   | prod0 11750 | 
. . . 4
⊢
∏𝑘 ∈
∅ 𝐵 =
1 | 
| 10 |   | 1ap0 8617 | 
. . . 4
⊢ 1 #
0 | 
| 11 | 9, 10 | eqbrtri 4054 | 
. . 3
⊢
∏𝑘 ∈
∅ 𝐵 #
0 | 
| 12 | 11 | a1i 9 | 
. 2
⊢ (𝜑 → ∏𝑘 ∈ ∅ 𝐵 # 0) | 
| 13 |   | simplr 528 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → 𝑦 ∈ Fin) | 
| 14 |   | simplll 533 | 
. . . . . . . 8
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ 𝑘 ∈ 𝑦) → 𝜑) | 
| 15 |   | simplrl 535 | 
. . . . . . . . 9
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ 𝑘 ∈ 𝑦) → 𝑦 ⊆ 𝐴) | 
| 16 |   | simpr 110 | 
. . . . . . . . 9
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ 𝑘 ∈ 𝑦) → 𝑘 ∈ 𝑦) | 
| 17 | 15, 16 | sseldd 3184 | 
. . . . . . . 8
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ 𝑘 ∈ 𝑦) → 𝑘 ∈ 𝐴) | 
| 18 |   | fprodn0.2 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐵 ∈ ℂ) | 
| 19 | 14, 17, 18 | syl2anc 411 | 
. . . . . . 7
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ 𝑘 ∈ 𝑦) → 𝐵 ∈ ℂ) | 
| 20 | 13, 19 | fprodcl 11772 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → ∏𝑘 ∈ 𝑦 𝐵 ∈ ℂ) | 
| 21 | 20 | adantr 276 | 
. . . . 5
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ ∏𝑘 ∈ 𝑦 𝐵 # 0) → ∏𝑘 ∈ 𝑦 𝐵 ∈ ℂ) | 
| 22 |   | simprr 531 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → 𝑧 ∈ (𝐴 ∖ 𝑦)) | 
| 23 | 22 | eldifad 3168 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → 𝑧 ∈ 𝐴) | 
| 24 | 18 | ralrimiva 2570 | 
. . . . . . . 8
⊢ (𝜑 → ∀𝑘 ∈ 𝐴 𝐵 ∈ ℂ) | 
| 25 | 24 | ad2antrr 488 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → ∀𝑘 ∈ 𝐴 𝐵 ∈ ℂ) | 
| 26 |   | rspcsbela 3144 | 
. . . . . . 7
⊢ ((𝑧 ∈ 𝐴 ∧ ∀𝑘 ∈ 𝐴 𝐵 ∈ ℂ) → ⦋𝑧 / 𝑘⦌𝐵 ∈ ℂ) | 
| 27 | 23, 25, 26 | syl2anc 411 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → ⦋𝑧 / 𝑘⦌𝐵 ∈ ℂ) | 
| 28 | 27 | adantr 276 | 
. . . . 5
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ ∏𝑘 ∈ 𝑦 𝐵 # 0) → ⦋𝑧 / 𝑘⦌𝐵 ∈ ℂ) | 
| 29 |   | simpr 110 | 
. . . . 5
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ ∏𝑘 ∈ 𝑦 𝐵 # 0) → ∏𝑘 ∈ 𝑦 𝐵 # 0) | 
| 30 |   | fprodap0.3 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐵 # 0) | 
| 31 | 30 | ralrimiva 2570 | 
. . . . . . . 8
⊢ (𝜑 → ∀𝑘 ∈ 𝐴 𝐵 # 0) | 
| 32 | 31 | ad2antrr 488 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → ∀𝑘 ∈ 𝐴 𝐵 # 0) | 
| 33 |   | nfcsb1v 3117 | 
. . . . . . . . 9
⊢
Ⅎ𝑘⦋𝑧 / 𝑘⦌𝐵 | 
| 34 |   | nfcv 2339 | 
. . . . . . . . 9
⊢
Ⅎ𝑘
# | 
| 35 |   | nfcv 2339 | 
. . . . . . . . 9
⊢
Ⅎ𝑘0 | 
| 36 | 33, 34, 35 | nfbr 4079 | 
. . . . . . . 8
⊢
Ⅎ𝑘⦋𝑧 / 𝑘⦌𝐵 # 0 | 
| 37 |   | csbeq1a 3093 | 
. . . . . . . . 9
⊢ (𝑘 = 𝑧 → 𝐵 = ⦋𝑧 / 𝑘⦌𝐵) | 
| 38 | 37 | breq1d 4043 | 
. . . . . . . 8
⊢ (𝑘 = 𝑧 → (𝐵 # 0 ↔ ⦋𝑧 / 𝑘⦌𝐵 # 0)) | 
| 39 | 36, 38 | rspc 2862 | 
. . . . . . 7
⊢ (𝑧 ∈ 𝐴 → (∀𝑘 ∈ 𝐴 𝐵 # 0 → ⦋𝑧 / 𝑘⦌𝐵 # 0)) | 
| 40 | 23, 32, 39 | sylc 62 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → ⦋𝑧 / 𝑘⦌𝐵 # 0) | 
| 41 | 40 | adantr 276 | 
. . . . 5
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ ∏𝑘 ∈ 𝑦 𝐵 # 0) → ⦋𝑧 / 𝑘⦌𝐵 # 0) | 
| 42 | 21, 28, 29, 41 | mulap0d 8685 | 
. . . 4
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ ∏𝑘 ∈ 𝑦 𝐵 # 0) → (∏𝑘 ∈ 𝑦 𝐵 · ⦋𝑧 / 𝑘⦌𝐵) # 0) | 
| 43 | 22 | eldifbd 3169 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → ¬ 𝑧 ∈ 𝑦) | 
| 44 | 33, 13, 22, 43, 19, 27, 37 | fprodunsn 11769 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → ∏𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 = (∏𝑘 ∈ 𝑦 𝐵 · ⦋𝑧 / 𝑘⦌𝐵)) | 
| 45 | 44 | breq1d 4043 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → (∏𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 # 0 ↔ (∏𝑘 ∈ 𝑦 𝐵 · ⦋𝑧 / 𝑘⦌𝐵) # 0)) | 
| 46 | 45 | adantr 276 | 
. . . 4
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ ∏𝑘 ∈ 𝑦 𝐵 # 0) → (∏𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 # 0 ↔ (∏𝑘 ∈ 𝑦 𝐵 · ⦋𝑧 / 𝑘⦌𝐵) # 0)) | 
| 47 | 42, 46 | mpbird 167 | 
. . 3
⊢ ((((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) ∧ ∏𝑘 ∈ 𝑦 𝐵 # 0) → ∏𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 # 0) | 
| 48 | 47 | ex 115 | 
. 2
⊢ (((𝜑 ∧ 𝑦 ∈ Fin) ∧ (𝑦 ⊆ 𝐴 ∧ 𝑧 ∈ (𝐴 ∖ 𝑦))) → (∏𝑘 ∈ 𝑦 𝐵 # 0 → ∏𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 # 0)) | 
| 49 |   | fprodn0.1 | 
. 2
⊢ (𝜑 → 𝐴 ∈ Fin) | 
| 50 | 2, 4, 6, 8, 12, 48, 49 | findcard2sd 6953 | 
1
⊢ (𝜑 → ∏𝑘 ∈ 𝐴 𝐵 # 0) |