Metamath Proof Explorer < Previous   Next > Nearby theorems Mirrors  >  Home  >  MPE Home  >  Th. List  >  wfrlem4 Structured version   Visualization version   GIF version

Theorem wfrlem4 7973
 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 ∧ (𝑥𝐴 ∧ ∀𝑦𝑥 Pred(𝑅, 𝐴, 𝑦) ⊆ 𝑥) ∧ ∀𝑦𝑥 (𝑓𝑦) = (𝐹‘(𝑓 ↾ Pred(𝑅, 𝐴, 𝑦))))}
Assertion
Ref Expression
wfrlem4 ((𝑔𝐵𝐵) → ((𝑔 ↾ (dom 𝑔 ∩ dom )) Fn (dom 𝑔 ∩ dom ) ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )((𝑔 ↾ (dom 𝑔 ∩ dom ))‘𝑎) = (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom )) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)))))
Distinct variable groups:   𝐴,𝑎,𝑓,𝑔,,𝑥,𝑦   𝐵,𝑎   𝐹,𝑎,𝑓,𝑔,,𝑥,𝑦   𝑅,𝑎,𝑓,𝑔,,𝑥,𝑦
Allowed substitution hints:   𝐵(𝑥,𝑦,𝑓,𝑔,)

Proof of Theorem wfrlem4
Dummy variables 𝑏 𝑐 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 wfrlem4.2 . . . . . 6 𝐵 = {𝑓 ∣ ∃𝑥(𝑓 Fn 𝑥 ∧ (𝑥𝐴 ∧ ∀𝑦𝑥 Pred(𝑅, 𝐴, 𝑦) ⊆ 𝑥) ∧ ∀𝑦𝑥 (𝑓𝑦) = (𝐹‘(𝑓 ↾ Pred(𝑅, 𝐴, 𝑦))))}
21wfrlem2 7970 . . . . 5 (𝑔𝐵 → Fun 𝑔)
32funfnd 6370 . . . 4 (𝑔𝐵𝑔 Fn dom 𝑔)
4 fnresin1 6459 . . . 4 (𝑔 Fn dom 𝑔 → (𝑔 ↾ (dom 𝑔 ∩ dom )) Fn (dom 𝑔 ∩ dom ))
53, 4syl 17 . . 3 (𝑔𝐵 → (𝑔 ↾ (dom 𝑔 ∩ dom )) Fn (dom 𝑔 ∩ dom ))
65adantr 484 . 2 ((𝑔𝐵𝐵) → (𝑔 ↾ (dom 𝑔 ∩ dom )) Fn (dom 𝑔 ∩ dom ))
71wfrlem1 7969 . . . . . . . 8 𝐵 = {𝑔 ∣ ∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))}
87abeq2i 2887 . . . . . . 7 (𝑔𝐵 ↔ ∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
9 fndm 6440 . . . . . . . . . . . 12 (𝑔 Fn 𝑏 → dom 𝑔 = 𝑏)
109raleqdv 3329 . . . . . . . . . . 11 (𝑔 Fn 𝑏 → (∀𝑎 ∈ dom 𝑔(𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ↔ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
1110biimpar 481 . . . . . . . . . 10 ((𝑔 Fn 𝑏 ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) → ∀𝑎 ∈ dom 𝑔(𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))
12 rsp 3134 . . . . . . . . . 10 (∀𝑎 ∈ dom 𝑔(𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) → (𝑎 ∈ dom 𝑔 → (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
1311, 12syl 17 . . . . . . . . 9 ((𝑔 Fn 𝑏 ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) → (𝑎 ∈ dom 𝑔 → (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
14133adant2 1128 . . . . . . . 8 ((𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) → (𝑎 ∈ dom 𝑔 → (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
1514exlimiv 1931 . . . . . . 7 (∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) → (𝑎 ∈ dom 𝑔 → (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
168, 15sylbi 220 . . . . . 6 (𝑔𝐵 → (𝑎 ∈ dom 𝑔 → (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))))
17 elinel1 4102 . . . . . 6 (𝑎 ∈ (dom 𝑔 ∩ dom ) → 𝑎 ∈ dom 𝑔)
1816, 17impel 509 . . . . 5 ((𝑔𝐵𝑎 ∈ (dom 𝑔 ∩ dom )) → (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))
1918adantlr 714 . . . 4 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))
20 fvres 6681 . . . . 5 (𝑎 ∈ (dom 𝑔 ∩ dom ) → ((𝑔 ↾ (dom 𝑔 ∩ dom ))‘𝑎) = (𝑔𝑎))
2120adantl 485 . . . 4 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → ((𝑔 ↾ (dom 𝑔 ∩ dom ))‘𝑎) = (𝑔𝑎))
22 resres 5840 . . . . . 6 ((𝑔 ↾ (dom 𝑔 ∩ dom )) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)) = (𝑔 ↾ ((dom 𝑔 ∩ dom ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)))
23 predss 6137 . . . . . . . . 9 Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎) ⊆ (dom 𝑔 ∩ dom )
24 sseqin2 4122 . . . . . . . . 9 (Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎) ⊆ (dom 𝑔 ∩ dom ) ↔ ((dom 𝑔 ∩ dom ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)) = Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎))
2523, 24mpbi 233 . . . . . . . 8 ((dom 𝑔 ∩ dom ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)) = Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)
261wfrlem1 7969 . . . . . . . . . . . 12 𝐵 = { ∣ ∃𝑐( Fn 𝑐 ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))}
2726abeq2i 2887 . . . . . . . . . . 11 (𝐵 ↔ ∃𝑐( Fn 𝑐 ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎)))))
28 3an6 1443 . . . . . . . . . . . . . 14 (((𝑔 Fn 𝑏 Fn 𝑐) ∧ ((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))) ↔ ((𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ( Fn 𝑐 ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))))
29282exbii 1850 . . . . . . . . . . . . 13 (∃𝑏𝑐((𝑔 Fn 𝑏 Fn 𝑐) ∧ ((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))) ↔ ∃𝑏𝑐((𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ( Fn 𝑐 ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))))
30 exdistrv 1956 . . . . . . . . . . . . 13 (∃𝑏𝑐((𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ( Fn 𝑐 ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))) ↔ (∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ∃𝑐( Fn 𝑐 ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))))
3129, 30bitri 278 . . . . . . . . . . . 12 (∃𝑏𝑐((𝑔 Fn 𝑏 Fn 𝑐) ∧ ((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))) ↔ (∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ∃𝑐( Fn 𝑐 ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))))
32 ssinss1 4144 . . . . . . . . . . . . . . . . . 18 (𝑏𝐴 → (𝑏𝑐) ⊆ 𝐴)
3332ad2antrr 725 . . . . . . . . . . . . . . . . 17 (((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → (𝑏𝑐) ⊆ 𝐴)
34 nfra1 3147 . . . . . . . . . . . . . . . . . . . 20 𝑎𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏
35 nfra1 3147 . . . . . . . . . . . . . . . . . . . 20 𝑎𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐
3634, 35nfan 1900 . . . . . . . . . . . . . . . . . . 19 𝑎(∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)
37 elinel1 4102 . . . . . . . . . . . . . . . . . . . . . 22 (𝑎 ∈ (𝑏𝑐) → 𝑎𝑏)
38 rsp 3134 . . . . . . . . . . . . . . . . . . . . . 22 (∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 → (𝑎𝑏 → Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏))
3937, 38syl5com 31 . . . . . . . . . . . . . . . . . . . . 21 (𝑎 ∈ (𝑏𝑐) → (∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 → Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏))
40 elinel2 4103 . . . . . . . . . . . . . . . . . . . . . 22 (𝑎 ∈ (𝑏𝑐) → 𝑎𝑐)
41 rsp 3134 . . . . . . . . . . . . . . . . . . . . . 22 (∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐 → (𝑎𝑐 → Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐))
4240, 41syl5com 31 . . . . . . . . . . . . . . . . . . . . 21 (𝑎 ∈ (𝑏𝑐) → (∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐 → Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐))
4339, 42anim12d 611 . . . . . . . . . . . . . . . . . . . 20 (𝑎 ∈ (𝑏𝑐) → ((∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) → (Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)))
44 ssin 4137 . . . . . . . . . . . . . . . . . . . . 21 ((Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ↔ Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐))
4544biimpi 219 . . . . . . . . . . . . . . . . . . . 20 ((Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) → Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐))
4643, 45syl6com 37 . . . . . . . . . . . . . . . . . . 19 ((∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) → (𝑎 ∈ (𝑏𝑐) → Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐)))
4736, 46ralrimi 3144 . . . . . . . . . . . . . . . . . 18 ((∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) → ∀𝑎 ∈ (𝑏𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐))
4847ad2ant2l 745 . . . . . . . . . . . . . . . . 17 (((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ∀𝑎 ∈ (𝑏𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐))
4933, 48jca 515 . . . . . . . . . . . . . . . 16 (((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((𝑏𝑐) ⊆ 𝐴 ∧ ∀𝑎 ∈ (𝑏𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐)))
50 fndm 6440 . . . . . . . . . . . . . . . . . 18 ( Fn 𝑐 → dom = 𝑐)
519, 50ineqan12d 4121 . . . . . . . . . . . . . . . . 17 ((𝑔 Fn 𝑏 Fn 𝑐) → (dom 𝑔 ∩ dom ) = (𝑏𝑐))
52 sseq1 3919 . . . . . . . . . . . . . . . . . . 19 ((dom 𝑔 ∩ dom ) = (𝑏𝑐) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ↔ (𝑏𝑐) ⊆ 𝐴))
53 sseq2 3920 . . . . . . . . . . . . . . . . . . . 20 ((dom 𝑔 ∩ dom ) = (𝑏𝑐) → (Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ) ↔ Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐)))
5453raleqbi1dv 3321 . . . . . . . . . . . . . . . . . . 19 ((dom 𝑔 ∩ dom ) = (𝑏𝑐) → (∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ) ↔ ∀𝑎 ∈ (𝑏𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐)))
5552, 54anbi12d 633 . . . . . . . . . . . . . . . . . 18 ((dom 𝑔 ∩ dom ) = (𝑏𝑐) → (((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom )) ↔ ((𝑏𝑐) ⊆ 𝐴 ∧ ∀𝑎 ∈ (𝑏𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐))))
5655imbi2d 344 . . . . . . . . . . . . . . . . 17 ((dom 𝑔 ∩ dom ) = (𝑏𝑐) → ((((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ))) ↔ (((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((𝑏𝑐) ⊆ 𝐴 ∧ ∀𝑎 ∈ (𝑏𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐)))))
5751, 56syl 17 . . . . . . . . . . . . . . . 16 ((𝑔 Fn 𝑏 Fn 𝑐) → ((((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ))) ↔ (((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((𝑏𝑐) ⊆ 𝐴 ∧ ∀𝑎 ∈ (𝑏𝑐)Pred(𝑅, 𝐴, 𝑎) ⊆ (𝑏𝑐)))))
5849, 57mpbiri 261 . . . . . . . . . . . . . . 15 ((𝑔 Fn 𝑏 Fn 𝑐) → (((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom ))))
5958imp 410 . . . . . . . . . . . . . 14 (((𝑔 Fn 𝑏 Fn 𝑐) ∧ ((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐))) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom )))
60593adant3 1129 . . . . . . . . . . . . 13 (((𝑔 Fn 𝑏 Fn 𝑐) ∧ ((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom )))
6160exlimivv 1933 . . . . . . . . . . . 12 (∃𝑏𝑐((𝑔 Fn 𝑏 Fn 𝑐) ∧ ((𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐)) ∧ (∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom )))
6231, 61sylbir 238 . . . . . . . . . . 11 ((∃𝑏(𝑔 Fn 𝑏 ∧ (𝑏𝐴 ∧ ∀𝑎𝑏 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑏) ∧ ∀𝑎𝑏 (𝑔𝑎) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))) ∧ ∃𝑐( Fn 𝑐 ∧ (𝑐𝐴 ∧ ∀𝑎𝑐 Pred(𝑅, 𝐴, 𝑎) ⊆ 𝑐) ∧ ∀𝑎𝑐 (𝑎) = (𝐹‘( ↾ Pred(𝑅, 𝐴, 𝑎))))) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom )))
638, 27, 62syl2anb 600 . . . . . . . . . 10 ((𝑔𝐵𝐵) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom )))
6463adantr 484 . . . . . . . . 9 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → ((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom )))
65 simpr 488 . . . . . . . . 9 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → 𝑎 ∈ (dom 𝑔 ∩ dom ))
66 preddowncl 6157 . . . . . . . . 9 (((dom 𝑔 ∩ dom ) ⊆ 𝐴 ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )Pred(𝑅, 𝐴, 𝑎) ⊆ (dom 𝑔 ∩ dom )) → (𝑎 ∈ (dom 𝑔 ∩ dom ) → Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎) = Pred(𝑅, 𝐴, 𝑎)))
6764, 65, 66sylc 65 . . . . . . . 8 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎) = Pred(𝑅, 𝐴, 𝑎))
6825, 67syl5eq 2805 . . . . . . 7 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → ((dom 𝑔 ∩ dom ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)) = Pred(𝑅, 𝐴, 𝑎))
6968reseq2d 5827 . . . . . 6 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → (𝑔 ↾ ((dom 𝑔 ∩ dom ) ∩ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎))) = (𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))
7022, 69syl5eq 2805 . . . . 5 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → ((𝑔 ↾ (dom 𝑔 ∩ dom )) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)) = (𝑔 ↾ Pred(𝑅, 𝐴, 𝑎)))
7170fveq2d 6666 . . . 4 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom )) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎))) = (𝐹‘(𝑔 ↾ Pred(𝑅, 𝐴, 𝑎))))
7219, 21, 713eqtr4d 2803 . . 3 (((𝑔𝐵𝐵) ∧ 𝑎 ∈ (dom 𝑔 ∩ dom )) → ((𝑔 ↾ (dom 𝑔 ∩ dom ))‘𝑎) = (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom )) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎))))
7372ralrimiva 3113 . 2 ((𝑔𝐵𝐵) → ∀𝑎 ∈ (dom 𝑔 ∩ dom )((𝑔 ↾ (dom 𝑔 ∩ dom ))‘𝑎) = (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom )) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎))))
746, 73jca 515 1 ((𝑔𝐵𝐵) → ((𝑔 ↾ (dom 𝑔 ∩ dom )) Fn (dom 𝑔 ∩ dom ) ∧ ∀𝑎 ∈ (dom 𝑔 ∩ dom )((𝑔 ↾ (dom 𝑔 ∩ dom ))‘𝑎) = (𝐹‘((𝑔 ↾ (dom 𝑔 ∩ dom )) ↾ Pred(𝑅, (dom 𝑔 ∩ dom ), 𝑎)))))
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ↔ wb 209   ∧ wa 399   ∧ w3a 1084   = wceq 1538  ∃wex 1781   ∈ wcel 2111  {cab 2735  ∀wral 3070   ∩ cin 3859   ⊆ wss 3860  dom cdm 5527   ↾ cres 5529  Predcpred 6129   Fn wfn 6334  ‘cfv 6339 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 2729  ax-sep 5172  ax-nul 5179  ax-pr 5301 This theorem depends on definitions:  df-bi 210  df-an 400  df-or 845  df-3an 1086  df-tru 1541  df-fal 1551  df-ex 1782  df-nf 1786  df-sb 2070  df-clab 2736  df-cleq 2750  df-clel 2830  df-nfc 2901  df-ral 3075  df-rex 3076  df-rab 3079  df-v 3411  df-sbc 3699  df-dif 3863  df-un 3865  df-in 3867  df-ss 3877  df-nul 4228  df-if 4424  df-sn 4526  df-pr 4528  df-op 4532  df-uni 4802  df-br 5036  df-opab 5098  df-xp 5533  df-rel 5534  df-cnv 5535  df-co 5536  df-dm 5537  df-rn 5538  df-res 5539  df-ima 5540  df-pred 6130  df-iota 6298  df-fun 6341  df-fn 6342  df-fv 6347 This theorem is referenced by:  wfrlem5  7974
 Copyright terms: Public domain W3C validator