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Theorem dfatbrafv2b 46538
Description: Equivalence of function value and binary relation, analogous to fnbrfvb 6944 or funbrfvb 6946. 𝐵 ∈ V is required, because otherwise 𝐴𝐹𝐵 ↔ ∅ ∈ 𝐹 can be true, but (𝐹''''𝐴) = 𝐵 is always false (because of dfatafv2ex 46506). (Contributed by AV, 6-Sep-2022.)
Assertion
Ref Expression
dfatbrafv2b ((𝐹 defAt 𝐴𝐵𝑊) → ((𝐹''''𝐴) = 𝐵𝐴𝐹𝐵))

Proof of Theorem dfatbrafv2b
Dummy variable 𝑥 is distinct from all other variables.
StepHypRef Expression
1 eqid 2727 . . . 4 (𝐹''''𝐴) = (𝐹''''𝐴)
2 dfatafv2ex 46506 . . . . . 6 (𝐹 defAt 𝐴 → (𝐹''''𝐴) ∈ V)
32adantr 480 . . . . 5 ((𝐹 defAt 𝐴𝐵𝑊) → (𝐹''''𝐴) ∈ V)
4 eqeq2 2739 . . . . . . 7 (𝑥 = (𝐹''''𝐴) → ((𝐹''''𝐴) = 𝑥 ↔ (𝐹''''𝐴) = (𝐹''''𝐴)))
5 breq2 5146 . . . . . . 7 (𝑥 = (𝐹''''𝐴) → (𝐴𝐹𝑥𝐴𝐹(𝐹''''𝐴)))
64, 5bibi12d 345 . . . . . 6 (𝑥 = (𝐹''''𝐴) → (((𝐹''''𝐴) = 𝑥𝐴𝐹𝑥) ↔ ((𝐹''''𝐴) = (𝐹''''𝐴) ↔ 𝐴𝐹(𝐹''''𝐴))))
76adantl 481 . . . . 5 (((𝐹 defAt 𝐴𝐵𝑊) ∧ 𝑥 = (𝐹''''𝐴)) → (((𝐹''''𝐴) = 𝑥𝐴𝐹𝑥) ↔ ((𝐹''''𝐴) = (𝐹''''𝐴) ↔ 𝐴𝐹(𝐹''''𝐴))))
8 dfdfat2 46421 . . . . . . 7 (𝐹 defAt 𝐴 ↔ (𝐴 ∈ dom 𝐹 ∧ ∃!𝑥 𝐴𝐹𝑥))
9 tz6.12c-afv2 46535 . . . . . . 7 (∃!𝑥 𝐴𝐹𝑥 → ((𝐹''''𝐴) = 𝑥𝐴𝐹𝑥))
108, 9simplbiim 504 . . . . . 6 (𝐹 defAt 𝐴 → ((𝐹''''𝐴) = 𝑥𝐴𝐹𝑥))
1110adantr 480 . . . . 5 ((𝐹 defAt 𝐴𝐵𝑊) → ((𝐹''''𝐴) = 𝑥𝐴𝐹𝑥))
123, 7, 11vtocld 3543 . . . 4 ((𝐹 defAt 𝐴𝐵𝑊) → ((𝐹''''𝐴) = (𝐹''''𝐴) ↔ 𝐴𝐹(𝐹''''𝐴)))
131, 12mpbii 232 . . 3 ((𝐹 defAt 𝐴𝐵𝑊) → 𝐴𝐹(𝐹''''𝐴))
14 breq2 5146 . . 3 ((𝐹''''𝐴) = 𝐵 → (𝐴𝐹(𝐹''''𝐴) ↔ 𝐴𝐹𝐵))
1513, 14syl5ibcom 244 . 2 ((𝐹 defAt 𝐴𝐵𝑊) → ((𝐹''''𝐴) = 𝐵𝐴𝐹𝐵))
16 df-dfat 46412 . . . 4 (𝐹 defAt 𝐴 ↔ (𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴})))
17 simpll 766 . . . . 5 (((𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴})) ∧ 𝐵𝑊) → 𝐴 ∈ dom 𝐹)
18 simpr 484 . . . . 5 (((𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴})) ∧ 𝐵𝑊) → 𝐵𝑊)
19 simpr 484 . . . . . 6 ((𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴})) → Fun (𝐹 ↾ {𝐴}))
2019adantr 480 . . . . 5 (((𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴})) ∧ 𝐵𝑊) → Fun (𝐹 ↾ {𝐴}))
2117, 18, 20jca31 514 . . . 4 (((𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴})) ∧ 𝐵𝑊) → ((𝐴 ∈ dom 𝐹𝐵𝑊) ∧ Fun (𝐹 ↾ {𝐴})))
2216, 21sylanb 580 . . 3 ((𝐹 defAt 𝐴𝐵𝑊) → ((𝐴 ∈ dom 𝐹𝐵𝑊) ∧ Fun (𝐹 ↾ {𝐴})))
23 funressnbrafv2 46537 . . 3 (((𝐴 ∈ dom 𝐹𝐵𝑊) ∧ Fun (𝐹 ↾ {𝐴})) → (𝐴𝐹𝐵 → (𝐹''''𝐴) = 𝐵))
2422, 23syl 17 . 2 ((𝐹 defAt 𝐴𝐵𝑊) → (𝐴𝐹𝐵 → (𝐹''''𝐴) = 𝐵))
2515, 24impbid 211 1 ((𝐹 defAt 𝐴𝐵𝑊) → ((𝐹''''𝐴) = 𝐵𝐴𝐹𝐵))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 205  wa 395   = wceq 1534  wcel 2099  ∃!weu 2557  Vcvv 3469  {csn 4624   class class class wbr 5142  dom cdm 5672  cres 5674  Fun wfun 6536   defAt wdfat 46409  ''''cafv2 46501
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1790  ax-4 1804  ax-5 1906  ax-6 1964  ax-7 2004  ax-8 2101  ax-9 2109  ax-10 2130  ax-11 2147  ax-12 2164  ax-ext 2698  ax-sep 5293  ax-nul 5300  ax-pow 5359  ax-pr 5423
This theorem depends on definitions:  df-bi 206  df-an 396  df-or 847  df-3an 1087  df-tru 1537  df-fal 1547  df-ex 1775  df-nf 1779  df-sb 2061  df-mo 2529  df-eu 2558  df-clab 2705  df-cleq 2719  df-clel 2805  df-nfc 2880  df-ne 2936  df-ral 3057  df-rex 3066  df-rab 3428  df-v 3471  df-dif 3947  df-un 3949  df-in 3951  df-ss 3961  df-nul 4319  df-if 4525  df-sn 4625  df-pr 4627  df-op 4631  df-uni 4904  df-br 5143  df-opab 5205  df-id 5570  df-xp 5678  df-rel 5679  df-cnv 5680  df-co 5681  df-dm 5682  df-res 5684  df-iota 6494  df-fun 6544  df-fn 6545  df-dfat 46412  df-afv2 46502
This theorem is referenced by:  dfatopafv2b  46539  dfatsnafv2  46545  dfatcolem  46548
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