| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | bnj153.1 | . 2
⊢ (𝜑 ↔ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅)) | 
| 2 |  | bnj153.2 | . 2
⊢ (𝜓 ↔ ∀𝑖 ∈ ω (suc 𝑖 ∈ 𝑛 → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))) | 
| 3 |  | bnj153.3 | . 2
⊢ 𝐷 = (ω ∖
{∅}) | 
| 4 |  | bnj153.4 | . 2
⊢ (𝜃 ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ∃!𝑓(𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓))) | 
| 5 |  | bnj153.5 | . 2
⊢ (𝜏 ↔ ∀𝑚 ∈ 𝐷 (𝑚 E 𝑛 → [𝑚 / 𝑛]𝜃)) | 
| 6 |  | biid 261 | . 2
⊢ (((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓)) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓))) | 
| 7 |  | biid 261 | . . . 4
⊢
([1o / 𝑛]𝜑 ↔ [1o / 𝑛]𝜑) | 
| 8 | 1, 7 | bnj118 34883 | . . 3
⊢
([1o / 𝑛]𝜑 ↔ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅)) | 
| 9 | 8 | bicomi 224 | . 2
⊢ ((𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ↔ [1o / 𝑛]𝜑) | 
| 10 |  | bnj105 34738 | . . . 4
⊢
1o ∈ V | 
| 11 | 2, 10 | bnj92 34876 | . . 3
⊢
([1o / 𝑛]𝜓 ↔ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))) | 
| 12 | 11 | bicomi 224 | . 2
⊢
(∀𝑖 ∈
ω (suc 𝑖 ∈
1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)) ↔ [1o / 𝑛]𝜓) | 
| 13 |  | biid 261 | . 2
⊢
([1o / 𝑛]𝜃 ↔ [1o / 𝑛]𝜃) | 
| 14 |  | biid 261 | . 2
⊢ (((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ∃𝑓(𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ∃𝑓(𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))))) | 
| 15 |  | biid 261 | . 2
⊢ (((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ∃*𝑓(𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ∃*𝑓(𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))))) | 
| 16 |  | biid 261 | . . . . 5
⊢
([1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓)) ↔ [1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓))) | 
| 17 |  | biid 261 | . . . . 5
⊢
([1o / 𝑛]𝜓 ↔ [1o / 𝑛]𝜓) | 
| 18 | 6, 16, 7, 17 | bnj121 34884 | . . . 4
⊢
([1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓)) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑 ∧ [1o / 𝑛]𝜓))) | 
| 19 | 8 | anbi2i 623 | . . . . . . 7
⊢ ((𝑓 Fn 1o ∧
[1o / 𝑛]𝜑) ↔ (𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅))) | 
| 20 | 19, 11 | anbi12i 628 | . . . . . 6
⊢ (((𝑓 Fn 1o ∧
[1o / 𝑛]𝜑) ∧ [1o / 𝑛]𝜓) ↔ ((𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅)) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 21 |  | df-3an 1089 | . . . . . 6
⊢ ((𝑓 Fn 1o ∧
[1o / 𝑛]𝜑 ∧ [1o / 𝑛]𝜓) ↔ ((𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑) ∧ [1o / 𝑛]𝜓)) | 
| 22 |  | df-3an 1089 | . . . . . 6
⊢ ((𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))) ↔ ((𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅)) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 23 | 20, 21, 22 | 3bitr4i 303 | . . . . 5
⊢ ((𝑓 Fn 1o ∧
[1o / 𝑛]𝜑 ∧ [1o / 𝑛]𝜓) ↔ (𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 24 | 23 | imbi2i 336 | . . . 4
⊢ (((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑 ∧ [1o / 𝑛]𝜓)) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))))) | 
| 25 | 18, 24 | bitri 275 | . . 3
⊢
([1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓)) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))))) | 
| 26 | 25 | bicomi 224 | . 2
⊢ (((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) ↔ [1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓))) | 
| 27 |  | eqid 2737 | . 2
⊢
{〈∅, pred(𝑥, 𝐴, 𝑅)〉} = {〈∅, pred(𝑥, 𝐴, 𝑅)〉} | 
| 28 |  | biid 261 | . 2
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓](𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ↔ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓](𝑓‘∅) = pred(𝑥, 𝐴, 𝑅)) | 
| 29 |  | biid 261 | . 2
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓]∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)) ↔ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓]∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))) | 
| 30 | 26 | sbcbii 3846 | . . 3
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) ↔ [{〈∅,
pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓))) | 
| 31 |  | biid 261 | . . . . 5
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑 ↔ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑) | 
| 32 |  | biid 261 | . . . . 5
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓 ↔ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓) | 
| 33 |  | biid 261 | . . . . 5
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓)) ↔ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓))) | 
| 34 | 27, 31, 32, 33, 18 | bnj124 34885 | . . . 4
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓)) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
[{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑 ∧ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓))) | 
| 35 | 1, 7, 31, 27 | bnj125 34886 | . . . . . . . 8
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑 ↔ ({〈∅, pred(𝑥, 𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅)) | 
| 36 | 35 | anbi2i 623 | . . . . . . 7
⊢
(({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
[{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑) ↔ ({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
({〈∅, pred(𝑥,
𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅))) | 
| 37 | 2, 17, 32, 27 | bnj126 34887 | . . . . . . 7
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓 ↔ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘suc 𝑖) = ∪ 𝑦 ∈ ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘𝑖) pred(𝑦, 𝐴, 𝑅))) | 
| 38 | 36, 37 | anbi12i 628 | . . . . . 6
⊢
((({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
[{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑) ∧ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓) ↔ (({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
({〈∅, pred(𝑥,
𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅)) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘suc 𝑖) = ∪ 𝑦 ∈ ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 39 |  | df-3an 1089 | . . . . . 6
⊢
(({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
[{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑 ∧ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓) ↔ (({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
[{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑) ∧ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓)) | 
| 40 |  | df-3an 1089 | . . . . . 6
⊢
(({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
({〈∅, pred(𝑥,
𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘suc 𝑖) = ∪ 𝑦 ∈ ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘𝑖) pred(𝑦, 𝐴, 𝑅))) ↔ (({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
({〈∅, pred(𝑥,
𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅)) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘suc 𝑖) = ∪ 𝑦 ∈ ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 41 | 38, 39, 40 | 3bitr4i 303 | . . . . 5
⊢
(({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
[{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑 ∧ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓) ↔ ({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
({〈∅, pred(𝑥,
𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘suc 𝑖) = ∪ 𝑦 ∈ ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 42 | 41 | imbi2i 336 | . . . 4
⊢ (((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
[{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜑 ∧ [{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]𝜓)) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
({〈∅, pred(𝑥,
𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘suc 𝑖) = ∪ 𝑦 ∈ ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘𝑖) pred(𝑦, 𝐴, 𝑅))))) | 
| 43 | 34, 42 | bitri 275 | . . 3
⊢
([{〈∅, pred(𝑥, 𝐴, 𝑅)〉} / 𝑓][1o / 𝑛]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓)) ↔ ((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
({〈∅, pred(𝑥,
𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘suc 𝑖) = ∪ 𝑦 ∈ ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘𝑖) pred(𝑦, 𝐴, 𝑅))))) | 
| 44 | 30, 43 | bitr2i 276 | . 2
⊢ (((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → ({〈∅, pred(𝑥, 𝐴, 𝑅)〉} Fn 1o ∧
({〈∅, pred(𝑥,
𝐴, 𝑅)〉}‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘suc 𝑖) = ∪ 𝑦 ∈ ({〈∅,
pred(𝑥, 𝐴, 𝑅)〉}‘𝑖) pred(𝑦, 𝐴, 𝑅)))) ↔ [{〈∅,
pred(𝑥, 𝐴, 𝑅)〉} / 𝑓]((𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))))) | 
| 45 |  | biid 261 | . 2
⊢ ((𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))) ↔ (𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 46 |  | biid 261 | . . . . 5
⊢ ((𝑓 Fn 1o ∧
[1o / 𝑛]𝜑 ∧ [1o / 𝑛]𝜓) ↔ (𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑 ∧ [1o / 𝑛]𝜓)) | 
| 47 |  | biid 261 | . . . . 5
⊢
([𝑔 / 𝑓](𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑 ∧ [1o / 𝑛]𝜓) ↔ [𝑔 / 𝑓](𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑 ∧ [1o / 𝑛]𝜓)) | 
| 48 |  | biid 261 | . . . . 5
⊢
([𝑔 / 𝑓][1o /
𝑛]𝜑 ↔ [𝑔 / 𝑓][1o / 𝑛]𝜑) | 
| 49 |  | biid 261 | . . . . 5
⊢
([𝑔 / 𝑓][1o /
𝑛]𝜓 ↔ [𝑔 / 𝑓][1o / 𝑛]𝜓) | 
| 50 | 46, 47, 48, 49 | bnj156 34742 | . . . 4
⊢
([𝑔 / 𝑓](𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑 ∧ [1o / 𝑛]𝜓) ↔ (𝑔 Fn 1o ∧ [𝑔 / 𝑓][1o / 𝑛]𝜑 ∧ [𝑔 / 𝑓][1o / 𝑛]𝜓)) | 
| 51 | 48, 8 | bnj154 34892 | . . . . . . 7
⊢
([𝑔 / 𝑓][1o /
𝑛]𝜑 ↔ (𝑔‘∅) = pred(𝑥, 𝐴, 𝑅)) | 
| 52 | 51 | anbi2i 623 | . . . . . 6
⊢ ((𝑔 Fn 1o ∧
[𝑔 / 𝑓][1o /
𝑛]𝜑) ↔ (𝑔 Fn 1o ∧ (𝑔‘∅) = pred(𝑥, 𝐴, 𝑅))) | 
| 53 | 17, 11 | bitri 275 | . . . . . . 7
⊢
([1o / 𝑛]𝜓 ↔ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))) | 
| 54 | 49, 53 | bnj155 34893 | . . . . . 6
⊢
([𝑔 / 𝑓][1o /
𝑛]𝜓 ↔ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑔‘suc 𝑖) = ∪ 𝑦 ∈ (𝑔‘𝑖) pred(𝑦, 𝐴, 𝑅))) | 
| 55 | 52, 54 | anbi12i 628 | . . . . 5
⊢ (((𝑔 Fn 1o ∧
[𝑔 / 𝑓][1o /
𝑛]𝜑) ∧ [𝑔 / 𝑓][1o / 𝑛]𝜓) ↔ ((𝑔 Fn 1o ∧ (𝑔‘∅) = pred(𝑥, 𝐴, 𝑅)) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑔‘suc 𝑖) = ∪ 𝑦 ∈ (𝑔‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 56 |  | df-3an 1089 | . . . . 5
⊢ ((𝑔 Fn 1o ∧
[𝑔 / 𝑓][1o /
𝑛]𝜑 ∧ [𝑔 / 𝑓][1o / 𝑛]𝜓) ↔ ((𝑔 Fn 1o ∧ [𝑔 / 𝑓][1o / 𝑛]𝜑) ∧ [𝑔 / 𝑓][1o / 𝑛]𝜓)) | 
| 57 |  | df-3an 1089 | . . . . 5
⊢ ((𝑔 Fn 1o ∧ (𝑔‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑔‘suc 𝑖) = ∪ 𝑦 ∈ (𝑔‘𝑖) pred(𝑦, 𝐴, 𝑅))) ↔ ((𝑔 Fn 1o ∧ (𝑔‘∅) = pred(𝑥, 𝐴, 𝑅)) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑔‘suc 𝑖) = ∪ 𝑦 ∈ (𝑔‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 58 | 55, 56, 57 | 3bitr4i 303 | . . . 4
⊢ ((𝑔 Fn 1o ∧
[𝑔 / 𝑓][1o /
𝑛]𝜑 ∧ [𝑔 / 𝑓][1o / 𝑛]𝜓) ↔ (𝑔 Fn 1o ∧ (𝑔‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑔‘suc 𝑖) = ∪ 𝑦 ∈ (𝑔‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 59 | 50, 58 | bitri 275 | . . 3
⊢
([𝑔 / 𝑓](𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑 ∧ [1o / 𝑛]𝜓) ↔ (𝑔 Fn 1o ∧ (𝑔‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑔‘suc 𝑖) = ∪ 𝑦 ∈ (𝑔‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 60 | 23 | sbcbii 3846 | . . 3
⊢
([𝑔 / 𝑓](𝑓 Fn 1o ∧ [1o
/ 𝑛]𝜑 ∧ [1o / 𝑛]𝜓) ↔ [𝑔 / 𝑓](𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 61 | 59, 60 | bitr3i 277 | . 2
⊢ ((𝑔 Fn 1o ∧ (𝑔‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑔‘suc 𝑖) = ∪ 𝑦 ∈ (𝑔‘𝑖) pred(𝑦, 𝐴, 𝑅))) ↔ [𝑔 / 𝑓](𝑓 Fn 1o ∧ (𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ∧ ∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)))) | 
| 62 |  | biid 261 | . 2
⊢
([𝑔 / 𝑓](𝑓‘∅) = pred(𝑥, 𝐴, 𝑅) ↔ [𝑔 / 𝑓](𝑓‘∅) = pred(𝑥, 𝐴, 𝑅)) | 
| 63 |  | biid 261 | . 2
⊢
([𝑔 / 𝑓]∀𝑖 ∈ ω (suc 𝑖 ∈ 1o →
(𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅)) ↔ [𝑔 / 𝑓]∀𝑖 ∈ ω (suc 𝑖 ∈ 1o → (𝑓‘suc 𝑖) = ∪ 𝑦 ∈ (𝑓‘𝑖) pred(𝑦, 𝐴, 𝑅))) | 
| 64 | 1, 2, 3, 4, 5, 6, 9, 12, 13, 14, 15, 26, 27, 28, 29, 44, 45, 61, 62, 63 | bnj151 34891 | 1
⊢ (𝑛 = 1o → ((𝑛 ∈ 𝐷 ∧ 𝜏) → 𝜃)) |