Theorem csbfrecsg 8220

Description: Move class substitution in and out of the well-founded recursive function generator. (Contributed by Scott Fenton, 18-Nov-2024.)

Assertion

Ref	Expression
csbfrecsg	⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌frecs(𝑅, 𝐷, 𝐹) = frecs(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, ⦋𝐴 / 𝑥⦌𝐹))

Proof of Theorem csbfrecsg

Dummy variables 𝑓 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		csbuni 4888	. . 3 ⊢ ⦋𝐴 / 𝑥⦌∪ {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))} = ∪ ⦋𝐴 / 𝑥⦌{𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))}
2		csbab 4389	. . . . 5 ⊢ ⦋𝐴 / 𝑥⦌{𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))} = {𝑓 ∣ [𝐴 / 𝑥]∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))}
3		sbcex2 3798	. . . . . . 7 ⊢ ([𝐴 / 𝑥]∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))) ↔ ∃𝑧[𝐴 / 𝑥](𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))))
4		sbc3an 3802	. . . . . . . . 9 ⊢ ([𝐴 / 𝑥](𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))) ↔ ([𝐴 / 𝑥]𝑓 Fn 𝑧 ∧ [𝐴 / 𝑥](𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ [𝐴 / 𝑥]∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))))
5		sbcg 3810	. . . . . . . . . 10 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]𝑓 Fn 𝑧 ↔ 𝑓 Fn 𝑧))
6		sbcan 3787	. . . . . . . . . . 11 ⊢ ([𝐴 / 𝑥](𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ↔ ([𝐴 / 𝑥]𝑧 ⊆ 𝐷 ∧ [𝐴 / 𝑥]∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧))
7		sbcssg 4469	. . . . . . . . . . . . 13 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]𝑧 ⊆ 𝐷 ↔ ⦋𝐴 / 𝑥⦌𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷))
8		csbconstg 3865	. . . . . . . . . . . . . 14 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌𝑧 = 𝑧)
9	8	sseq1d 3962	. . . . . . . . . . . . 13 ⊢ (𝐴 ∈ 𝑉 → (⦋𝐴 / 𝑥⦌𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ↔ 𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷))
10	7, 9	bitrd 279	. . . . . . . . . . . 12 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]𝑧 ⊆ 𝐷 ↔ 𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷))
11		sbcralg 3821	. . . . . . . . . . . . 13 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧 ↔ ∀𝑦 ∈ 𝑧 [𝐴 / 𝑥]Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧))
12		sbcssg 4469	. . . . . . . . . . . . . . 15 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧 ↔ ⦋𝐴 / 𝑥⦌Pred(𝑅, 𝐷, 𝑦) ⊆ ⦋𝐴 / 𝑥⦌𝑧))
13		csbpredg 6259	. . . . . . . . . . . . . . . . 17 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌Pred(𝑅, 𝐷, 𝑦) = Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, ⦋𝐴 / 𝑥⦌𝑦))
14		csbconstg 3865	. . . . . . . . . . . . . . . . . 18 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌𝑦 = 𝑦)
15		predeq3 6257	. . . . . . . . . . . . . . . . . 18 ⊢ (⦋𝐴 / 𝑥⦌𝑦 = 𝑦 → Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, ⦋𝐴 / 𝑥⦌𝑦) = Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))
16	14, 15	syl 17	. . . . . . . . . . . . . . . . 17 ⊢ (𝐴 ∈ 𝑉 → Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, ⦋𝐴 / 𝑥⦌𝑦) = Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))
17	13, 16	eqtrd 2768	. . . . . . . . . . . . . . . 16 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌Pred(𝑅, 𝐷, 𝑦) = Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))
18	17, 8	sseq12d 3964	. . . . . . . . . . . . . . 15 ⊢ (𝐴 ∈ 𝑉 → (⦋𝐴 / 𝑥⦌Pred(𝑅, 𝐷, 𝑦) ⊆ ⦋𝐴 / 𝑥⦌𝑧 ↔ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧))
19	12, 18	bitrd 279	. . . . . . . . . . . . . 14 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧 ↔ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧))
20	19	ralbidv 3156	. . . . . . . . . . . . 13 ⊢ (𝐴 ∈ 𝑉 → (∀𝑦 ∈ 𝑧 [𝐴 / 𝑥]Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧 ↔ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧))
21	11, 20	bitrd 279	. . . . . . . . . . . 12 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧 ↔ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧))
22	10, 21	anbi12d 632	. . . . . . . . . . 11 ⊢ (𝐴 ∈ 𝑉 → (([𝐴 / 𝑥]𝑧 ⊆ 𝐷 ∧ [𝐴 / 𝑥]∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ↔ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧)))
23	6, 22	bitrid 283	. . . . . . . . . 10 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥](𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ↔ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧)))
24		sbcralg 3821	. . . . . . . . . . 11 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) ↔ ∀𝑦 ∈ 𝑧 [𝐴 / 𝑥](𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))))
25		sbceqg 4361	. . . . . . . . . . . . 13 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥](𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) ↔ ⦋𝐴 / 𝑥⦌(𝑓‘𝑦) = ⦋𝐴 / 𝑥⦌(𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))))
26		csbconstg 3865	. . . . . . . . . . . . . 14 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌(𝑓‘𝑦) = (𝑓‘𝑦))
27		csbov123 7396	. . . . . . . . . . . . . . 15 ⊢ ⦋𝐴 / 𝑥⦌(𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) = (⦋𝐴 / 𝑥⦌𝑦⦋𝐴 / 𝑥⦌𝐹⦋𝐴 / 𝑥⦌(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))
28		csbres 5935	. . . . . . . . . . . . . . . . 17 ⊢ ⦋𝐴 / 𝑥⦌(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)) = (⦋𝐴 / 𝑥⦌𝑓 ↾ ⦋𝐴 / 𝑥⦌Pred(𝑅, 𝐷, 𝑦))
29		csbconstg 3865	. . . . . . . . . . . . . . . . . 18 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌𝑓 = 𝑓)
30	29, 17	reseq12d 5933	. . . . . . . . . . . . . . . . 17 ⊢ (𝐴 ∈ 𝑉 → (⦋𝐴 / 𝑥⦌𝑓 ↾ ⦋𝐴 / 𝑥⦌Pred(𝑅, 𝐷, 𝑦)) = (𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦)))
31	28, 30	eqtrid 2780	. . . . . . . . . . . . . . . 16 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)) = (𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦)))
32	14, 31	oveq12d 7370	. . . . . . . . . . . . . . 15 ⊢ (𝐴 ∈ 𝑉 → (⦋𝐴 / 𝑥⦌𝑦⦋𝐴 / 𝑥⦌𝐹⦋𝐴 / 𝑥⦌(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))
33	27, 32	eqtrid 2780	. . . . . . . . . . . . . 14 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌(𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))
34	26, 33	eqeq12d 2749	. . . . . . . . . . . . 13 ⊢ (𝐴 ∈ 𝑉 → (⦋𝐴 / 𝑥⦌(𝑓‘𝑦) = ⦋𝐴 / 𝑥⦌(𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) ↔ (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦)))))
35	25, 34	bitrd 279	. . . . . . . . . . . 12 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥](𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) ↔ (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦)))))
36	35	ralbidv 3156	. . . . . . . . . . 11 ⊢ (𝐴 ∈ 𝑉 → (∀𝑦 ∈ 𝑧 [𝐴 / 𝑥](𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) ↔ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦)))))
37	24, 36	bitrd 279	. . . . . . . . . 10 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))) ↔ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦)))))
38	5, 23, 37	3anbi123d 1438	. . . . . . . . 9 ⊢ (𝐴 ∈ 𝑉 → (([𝐴 / 𝑥]𝑓 Fn 𝑧 ∧ [𝐴 / 𝑥](𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ [𝐴 / 𝑥]∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))) ↔ (𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))))
39	4, 38	bitrid 283	. . . . . . . 8 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥](𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))) ↔ (𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))))
40	39	exbidv 1922	. . . . . . 7 ⊢ (𝐴 ∈ 𝑉 → (∃𝑧[𝐴 / 𝑥](𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))) ↔ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))))
41	3, 40	bitrid 283	. . . . . 6 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦)))) ↔ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))))
42	41	abbidv 2799	. . . . 5 ⊢ (𝐴 ∈ 𝑉 → {𝑓 ∣ [𝐴 / 𝑥]∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))} = {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))})
43	2, 42	eqtrid 2780	. . . 4 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌{𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))} = {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))})
44	43	unieqd 4871	. . 3 ⊢ (𝐴 ∈ 𝑉 → ∪ ⦋𝐴 / 𝑥⦌{𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))} = ∪ {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))})
45	1, 44	eqtrid 2780	. 2 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌∪ {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))} = ∪ {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))})
46		df-frecs 8217	. . 3 ⊢ frecs(𝑅, 𝐷, 𝐹) = ∪ {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))}
47	46	csbeq2i 3854	. 2 ⊢ ⦋𝐴 / 𝑥⦌frecs(𝑅, 𝐷, 𝐹) = ⦋𝐴 / 𝑥⦌∪ {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ 𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(𝑅, 𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦𝐹(𝑓 ↾ Pred(𝑅, 𝐷, 𝑦))))}
48		df-frecs 8217	. 2 ⊢ frecs(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, ⦋𝐴 / 𝑥⦌𝐹) = ∪ {𝑓 ∣ ∃𝑧(𝑓 Fn 𝑧 ∧ (𝑧 ⊆ ⦋𝐴 / 𝑥⦌𝐷 ∧ ∀𝑦 ∈ 𝑧 Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦) ⊆ 𝑧) ∧ ∀𝑦 ∈ 𝑧 (𝑓‘𝑦) = (𝑦⦋𝐴 / 𝑥⦌𝐹(𝑓 ↾ Pred(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, 𝑦))))}
49	45, 47, 48	3eqtr4g 2793	1 ⊢ (𝐴 ∈ 𝑉 → ⦋𝐴 / 𝑥⦌frecs(𝑅, 𝐷, 𝐹) = frecs(⦋𝐴 / 𝑥⦌𝑅, ⦋𝐴 / 𝑥⦌𝐷, ⦋𝐴 / 𝑥⦌𝐹))

Syntax hints:   → wi 4   ∧ wa 395   ∧ w3a 1086   = wceq 1541  ∃wex 1780   ∈ wcel 2113  {cab 2711  ∀wral 3048  [wsbc 3737  ⦋csb 3846   ⊆ wss 3898  ∪ cuni 4858   ↾ cres 5621  Predcpred 6252   Fn wfn 6481  ‘cfv 6486  (class class class)co 7352  frecscfrecs 8216

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-10 2146  ax-11 2162  ax-12 2182  ax-ext 2705  ax-sep 5236  ax-nul 5246  ax-pr 5372

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1544  df-fal 1554  df-ex 1781  df-nf 1785  df-sb 2068  df-mo 2537  df-eu 2566  df-clab 2712  df-cleq 2725  df-clel 2808  df-nfc 2882  df-ne 2930  df-ral 3049  df-rex 3058  df-rab 3397  df-v 3439  df-sbc 3738  df-csb 3847  df-dif 3901  df-un 3903  df-in 3905  df-ss 3915  df-nul 4283  df-if 4475  df-sn 4576  df-pr 4578  df-op 4582  df-uni 4859  df-br 5094  df-opab 5156  df-xp 5625  df-cnv 5627  df-dm 5629  df-rn 5630  df-res 5631  df-ima 5632  df-pred 6253  df-iota 6442  df-fv 6494  df-ov 7355  df-frecs 8217

This theorem is referenced by:  csbwrecsg  8254