wfrlem4 - Metamath Proof Explorer

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Theorem wfrlem4 7941

Description: Lemma for well-founded recursion. Properties of the restriction of an acceptable function to the domain of another one. (Contributed by Scott Fenton, 21-Apr-2011.) (Revised by AV, 18-Jul-2022.)

**Hypothesis**
Ref	Expression
wfrlem4.2	⊢ 𝐵 = {𝑓 ∣ ∃𝑥(𝑓 Fn 𝑥 ∧ (𝑥 ⊆ 𝐴 ∧ ∀𝑦 ∈ 𝑥 Pred(𝑅, 𝐴, 𝑦) ⊆ 𝑥) ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ Pred(𝑅, 𝐴, 𝑦))))}

**Assertion**
Ref	Expression
wfrlem4	⊢ ((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) → ((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) Fn (dom 𝑔 ∩ dom ℎ) ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)((𝑔 ↾ (dom 𝑔 ∩ dom ℎ))‘𝑎) = (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)))))

Distinct variable groups: 𝐴,𝑎,𝑓,𝑔,ℎ,𝑥,𝑦 𝐵,𝑎 𝐹,𝑎,𝑓,𝑔,ℎ,𝑥,𝑦 𝑅,𝑎,𝑓,𝑔,ℎ,𝑥,𝑦 Allowed substitution hints: 𝐵(𝑥,𝑦,𝑓,𝑔,ℎ)

Proof of Theorem wfrlem4 Dummy variables 𝑏 𝑐 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		wfrlem4.2	. . . . . 6 ⊢ 𝐵 = {𝑓 ∣ ∃𝑥(𝑓 Fn 𝑥 ∧ (𝑥 ⊆ 𝐴 ∧ ∀𝑦 ∈ 𝑥 Pred(𝑅, 𝐴, 𝑦) ⊆ 𝑥) ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ Pred(𝑅, 𝐴, 𝑦))))}
2	1	wfrlem2 7938	. . . . 5 ⊢ (𝑔 ∈ 𝐵 → Fun 𝑔)
3	2	funfnd 6355	. . . 4 ⊢ (𝑔 ∈ 𝐵 → 𝑔 Fn dom 𝑔)
4		fnresin1 6444	. . . 4 ⊢ (𝑔 Fn dom 𝑔 → (𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) Fn (dom 𝑔 ∩ dom ℎ))
5	3, 4	syl 17	. . 3 ⊢ (𝑔 ∈ 𝐵 → (𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) Fn (dom 𝑔 ∩ dom ℎ))
6	5	adantr 484	. 2 ⊢ ((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) → (𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) Fn (dom 𝑔 ∩ dom ℎ))
7	1	wfrlem1 7937	. . . . . . . 8 ⊢ 𝐵 = {𝑔 ∣ ∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))}
8	7	abeq2i 2925	. . . . . . 7 ⊢ (𝑔 ∈ 𝐵 ↔ ∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
9		fndm 6425	. . . . . . . . . . . 12 ⊢ (𝑔 Fn 𝑏 → dom 𝑔 = 𝑏)
10	9	raleqdv 3364	. . . . . . . . . . 11 ⊢ (𝑔 Fn 𝑏 → (∀𝑎 ∈ dom 𝑔(𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ↔ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
11	10	biimpar 481	. . . . . . . . . 10 ⊢ ((𝑔 Fn 𝑏 ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) → ∀𝑎 ∈ dom 𝑔(𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))
12		rsp 3170	. . . . . . . . . 10 ⊢ (∀𝑎 ∈ dom 𝑔(𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) → (𝑎 ∈ dom 𝑔 → (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
13	11, 12	syl 17	. . . . . . . . 9 ⊢ ((𝑔 Fn 𝑏 ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) → (𝑎 ∈ dom 𝑔 → (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
14	13	3adant2 1128	. . . . . . . 8 ⊢ ((𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) → (𝑎 ∈ dom 𝑔 → (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
15	14	exlimiv 1931	. . . . . . 7 ⊢ (∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) → (𝑎 ∈ dom 𝑔 → (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
16	8, 15	sylbi 220	. . . . . 6 ⊢ (𝑔 ∈ 𝐵 → (𝑎 ∈ dom 𝑔 → (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
17		elinel1 4122	. . . . . 6 ⊢ (𝑎 ∈ (dom 𝑔 ∩ dom ℎ) → 𝑎 ∈ dom 𝑔)
18	16, 17	impel 509	. . . . 5 ⊢ ((𝑔 ∈ 𝐵 ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))
19	18	adantlr 714	. . . 4 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))
20		fvres 6664	. . . . 5 ⊢ (𝑎 ∈ (dom 𝑔 ∩ dom ℎ) → ((𝑔 ↾ (dom 𝑔 ∩ dom ℎ))‘𝑎) = (𝑔‘𝑎))
21	20	adantl 485	. . . 4 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → ((𝑔 ↾ (dom 𝑔 ∩ dom ℎ))‘𝑎) = (𝑔‘𝑎))
22		resres 5831	. . . . . 6 ⊢ ((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)) = (𝑔 ↾ ((dom 𝑔 ∩ dom ℎ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)))
23		predss 6123	. . . . . . . . 9 ⊢ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)
24		sseqin2 4142	. . . . . . . . 9 ⊢ (Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ) ↔ ((dom 𝑔 ∩ dom ℎ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)) = Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎))
25	23, 24	mpbi 233	. . . . . . . 8 ⊢ ((dom 𝑔 ∩ dom ℎ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)) = Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)
26	1	wfrlem1 7937	. . . . . . . . . . . 12 ⊢ 𝐵 = {ℎ ∣ ∃𝑐(ℎ Fn 𝑐 ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))}
27	26	abeq2i 2925	. . . . . . . . . . 11 ⊢ (ℎ ∈ 𝐵 ↔ ∃𝑐(ℎ Fn 𝑐 ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎)))))
28		3an6 1443	. . . . . . . . . . . . . 14 ⊢ (((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) ∧ ((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))) ↔ ((𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ (ℎ Fn 𝑐 ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))))
29	28	2exbii 1850	. . . . . . . . . . . . 13 ⊢ (∃𝑏∃𝑐((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) ∧ ((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))) ↔ ∃𝑏∃𝑐((𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ (ℎ Fn 𝑐 ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))))
30		exdistrv 1956	. . . . . . . . . . . . 13 ⊢ (∃𝑏∃𝑐((𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ (ℎ Fn 𝑐 ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))) ↔ (∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ∃𝑐(ℎ Fn 𝑐 ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))))
31	29, 30	bitri 278	. . . . . . . . . . . 12 ⊢ (∃𝑏∃𝑐((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) ∧ ((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))) ↔ (∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ∃𝑐(ℎ Fn 𝑐 ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))))
32		ssinss1 4164	. . . . . . . . . . . . . . . . . 18 ⊢ (𝑏 ⊆ 𝐴 → (𝑏 ∩ 𝑐) ⊆ 𝐴)
33	32	ad2antrr 725	. . . . . . . . . . . . . . . . 17 ⊢ (((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → (𝑏 ∩ 𝑐) ⊆ 𝐴)
34		nfra1 3183	. . . . . . . . . . . . . . . . . . . 20 ⊢ Ⅎ𝑎∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏
35		nfra1 3183	. . . . . . . . . . . . . . . . . . . 20 ⊢ Ⅎ𝑎∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐
36	34, 35	nfan 1900	. . . . . . . . . . . . . . . . . . 19 ⊢ Ⅎ𝑎(∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)
37		elinel1 4122	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑎 ∈ (𝑏 ∩ 𝑐) → 𝑎 ∈ 𝑏)
38		rsp 3170	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 → (𝑎 ∈ 𝑏 → Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏))
39	37, 38	syl5com 31	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑎 ∈ (𝑏 ∩ 𝑐) → (∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 → Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏))
40		elinel2 4123	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑎 ∈ (𝑏 ∩ 𝑐) → 𝑎 ∈ 𝑐)
41		rsp 3170	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐 → (𝑎 ∈ 𝑐 → Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐))
42	40, 41	syl5com 31	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑎 ∈ (𝑏 ∩ 𝑐) → (∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐 → Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐))
43	39, 42	anim12d 611	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑎 ∈ (𝑏 ∩ 𝑐) → ((∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) → (Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)))
44		ssin 4157	. . . . . . . . . . . . . . . . . . . . 21 ⊢ ((Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ↔ Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐))
45	44	biimpi 219	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) → Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐))
46	43, 45	syl6com 37	. . . . . . . . . . . . . . . . . . 19 ⊢ ((∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) → (𝑎 ∈ (𝑏 ∩ 𝑐) → Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐)))
47	36, 46	ralrimi 3180	. . . . . . . . . . . . . . . . . 18 ⊢ ((∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) → ∀𝑎 ∈ (𝑏 ∩ 𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐))
48	47	ad2ant2l 745	. . . . . . . . . . . . . . . . 17 ⊢ (((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ∀𝑎 ∈ (𝑏 ∩ 𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐))
49	33, 48	jca 515	. . . . . . . . . . . . . . . 16 ⊢ (((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((𝑏 ∩ 𝑐) ⊆ 𝐴 ∧ ∀𝑎 ∈ (𝑏 ∩ 𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐)))
50		fndm 6425	. . . . . . . . . . . . . . . . . 18 ⊢ (ℎ Fn 𝑐 → dom ℎ = 𝑐)
51	9, 50	ineqan12d 4141	. . . . . . . . . . . . . . . . 17 ⊢ ((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) → (dom 𝑔 ∩ dom ℎ) = (𝑏 ∩ 𝑐))
52		sseq1 3940	. . . . . . . . . . . . . . . . . . 19 ⊢ ((dom 𝑔 ∩ dom ℎ) = (𝑏 ∩ 𝑐) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ↔ (𝑏 ∩ 𝑐) ⊆ 𝐴))
53		sseq2 3941	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((dom 𝑔 ∩ dom ℎ) = (𝑏 ∩ 𝑐) → (Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ) ↔ Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐)))
54	53	raleqbi1dv 3356	. . . . . . . . . . . . . . . . . . 19 ⊢ ((dom 𝑔 ∩ dom ℎ) = (𝑏 ∩ 𝑐) → (∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ) ↔ ∀𝑎 ∈ (𝑏 ∩ 𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐)))
55	52, 54	anbi12d 633	. . . . . . . . . . . . . . . . . 18 ⊢ ((dom 𝑔 ∩ dom ℎ) = (𝑏 ∩ 𝑐) → (((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)) ↔ ((𝑏 ∩ 𝑐) ⊆ 𝐴 ∧ ∀𝑎 ∈ (𝑏 ∩ 𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐))))
56	55	imbi2d 344	. . . . . . . . . . . . . . . . 17 ⊢ ((dom 𝑔 ∩ dom ℎ) = (𝑏 ∩ 𝑐) → ((((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ))) ↔ (((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((𝑏 ∩ 𝑐) ⊆ 𝐴 ∧ ∀𝑎 ∈ (𝑏 ∩ 𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐)))))
57	51, 56	syl 17	. . . . . . . . . . . . . . . 16 ⊢ ((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) → ((((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ))) ↔ (((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((𝑏 ∩ 𝑐) ⊆ 𝐴 ∧ ∀𝑎 ∈ (𝑏 ∩ 𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏 ∩ 𝑐)))))
58	49, 57	mpbiri 261	. . . . . . . . . . . . . . 15 ⊢ ((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) → (((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ))))
59	58	imp 410	. . . . . . . . . . . . . 14 ⊢ (((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) ∧ ((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐))) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)))
60	59	3adant3 1129	. . . . . . . . . . . . 13 ⊢ (((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) ∧ ((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)))
61	60	exlimivv 1933	. . . . . . . . . . . 12 ⊢ (∃𝑏∃𝑐((𝑔 Fn 𝑏 ∧ ℎ Fn 𝑐) ∧ ((𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)))
62	31, 61	sylbir 238	. . . . . . . . . . 11 ⊢ ((∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎 ∈ 𝑏 (𝑔‘𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ∃𝑐(ℎ Fn 𝑐 ∧ (𝑐 ⊆ 𝐴 ∧ ∀𝑎 ∈ 𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎 ∈ 𝑐 (ℎ‘𝑎) = (𝐹‘(ℎ ↾ Pred(𝑅, 𝐴, 𝑎))))) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)))
63	8, 27, 62	syl2anb 600	. . . . . . . . . 10 ⊢ ((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)))
64	63	adantr 484	. . . . . . . . 9 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → ((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)))
65		simpr 488	. . . . . . . . 9 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → 𝑎 ∈ (dom 𝑔 ∩ dom ℎ))
66		preddowncl 6143	. . . . . . . . 9 ⊢ (((dom 𝑔 ∩ dom ℎ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ℎ)) → (𝑎 ∈ (dom 𝑔 ∩ dom ℎ) → Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎) = Pred(𝑅, 𝐴, 𝑎)))
67	64, 65, 66	sylc 65	. . . . . . . 8 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎) = Pred(𝑅, 𝐴, 𝑎))
68	25, 67	syl5eq 2845	. . . . . . 7 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → ((dom 𝑔 ∩ dom ℎ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)) = Pred(𝑅, 𝐴, 𝑎))
69	68	reseq2d 5818	. . . . . 6 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → (𝑔 ↾ ((dom 𝑔 ∩ dom ℎ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎))) = (𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))
70	22, 69	syl5eq 2845	. . . . 5 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → ((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)) = (𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))
71	70	fveq2d 6649	. . . 4 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎))) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))
72	19, 21, 71	3eqtr4d 2843	. . 3 ⊢ (((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom ℎ)) → ((𝑔 ↾ (dom 𝑔 ∩ dom ℎ))‘𝑎) = (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎))))
73	72	ralrimiva 3149	. 2 ⊢ ((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) → ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)((𝑔 ↾ (dom 𝑔 ∩ dom ℎ))‘𝑎) = (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎))))
74	6, 73	jca 515	1 ⊢ ((𝑔 ∈ 𝐵 ∧ ℎ ∈ 𝐵) → ((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) Fn (dom 𝑔 ∩ dom ℎ) ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom ℎ)((𝑔 ↾ (dom 𝑔 ∩ dom ℎ))‘𝑎) = (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom ℎ)) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ℎ), 𝑎)))))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 209 ∧ wa 399 ∧ w3a 1084 = wceq 1538 ∃wex 1781 ∈ wcel 2111 {cab 2776 ∀wral 3106 ∩ cin 3880 ⊆ wss 3881 dom cdm 5519 ↾ cres 5521 Predcpred 6115 Fn wfn 6319 ‘cfv 6324

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2113 ax-9 2121 ax-10 2142 ax-11 2158 ax-12 2175 ax-ext 2770 ax-sep 5167 ax-nul 5174 ax-pr 5295

This theorem depends on definitions: df-bi 210 df-an 400 df-or 845 df-3an 1086 df-tru 1541 df-ex 1782 df-nf 1786 df-sb 2070 df-mo 2598 df-eu 2629 df-clab 2777 df-cleq 2791 df-clel 2870 df-nfc 2938 df-ral 3111 df-rex 3112 df-rab 3115 df-v 3443 df-sbc 3721 df-dif 3884 df-un 3886 df-in 3888 df-ss 3898 df-nul 4244 df-if 4426 df-sn 4526 df-pr 4528 df-op 4532 df-uni 4801 df-br 5031 df-opab 5093 df-xp 5525 df-rel 5526 df-cnv 5527 df-co 5528 df-dm 5529 df-rn 5530 df-res 5531 df-ima 5532 df-pred 6116 df-iota 6283 df-fun 6326 df-fn 6327 df-fv 6332

This theorem is referenced by: wfrlem5 7942

W3C validator