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Theorem rexima 5421
Description: Existential quantification under an image in terms of the base set. (Contributed by Stefan O'Rear, 21-Jan-2015.)
Hypothesis
Ref Expression
rexima.x (𝑥 = (𝐹𝑦) → (𝜑𝜓))
Assertion
Ref Expression
rexima ((𝐹 Fn 𝐴𝐵𝐴) → (∃𝑥 ∈ (𝐹𝐵)𝜑 ↔ ∃𝑦𝐵 𝜓))
Distinct variable groups:   𝜑,𝑦   𝜓,𝑥   𝑥,𝐹,𝑦   𝑥,𝐵,𝑦   𝑥,𝐴,𝑦
Allowed substitution hints:   𝜑(𝑥)   𝜓(𝑦)

Proof of Theorem rexima
StepHypRef Expression
1 ssel2 2967 . . . 4 ((𝐵𝐴𝑦𝐵) → 𝑦𝐴)
2 funfvex 5219 . . . . 5 ((Fun 𝐹𝑦 ∈ dom 𝐹) → (𝐹𝑦) ∈ V)
32funfni 5026 . . . 4 ((𝐹 Fn 𝐴𝑦𝐴) → (𝐹𝑦) ∈ V)
41, 3sylan2 274 . . 3 ((𝐹 Fn 𝐴 ∧ (𝐵𝐴𝑦𝐵)) → (𝐹𝑦) ∈ V)
54anassrs 386 . 2 (((𝐹 Fn 𝐴𝐵𝐴) ∧ 𝑦𝐵) → (𝐹𝑦) ∈ V)
6 fvelimab 5256 . . 3 ((𝐹 Fn 𝐴𝐵𝐴) → (𝑥 ∈ (𝐹𝐵) ↔ ∃𝑦𝐵 (𝐹𝑦) = 𝑥))
7 eqcom 2058 . . . 4 ((𝐹𝑦) = 𝑥𝑥 = (𝐹𝑦))
87rexbii 2348 . . 3 (∃𝑦𝐵 (𝐹𝑦) = 𝑥 ↔ ∃𝑦𝐵 𝑥 = (𝐹𝑦))
96, 8syl6bb 189 . 2 ((𝐹 Fn 𝐴𝐵𝐴) → (𝑥 ∈ (𝐹𝐵) ↔ ∃𝑦𝐵 𝑥 = (𝐹𝑦)))
10 rexima.x . . 3 (𝑥 = (𝐹𝑦) → (𝜑𝜓))
1110adantl 266 . 2 (((𝐹 Fn 𝐴𝐵𝐴) ∧ 𝑥 = (𝐹𝑦)) → (𝜑𝜓))
125, 9, 11rexxfr2d 4224 1 ((𝐹 Fn 𝐴𝐵𝐴) → (∃𝑥 ∈ (𝐹𝐵)𝜑 ↔ ∃𝑦𝐵 𝜓))
Colors of variables: wff set class
Syntax hints:  wi 4  wa 101  wb 102   = wceq 1259  wcel 1409  wrex 2324  Vcvv 2574  wss 2944  cima 4375   Fn wfn 4924  cfv 4929
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-io 640  ax-5 1352  ax-7 1353  ax-gen 1354  ax-ie1 1398  ax-ie2 1399  ax-8 1411  ax-10 1412  ax-11 1413  ax-i12 1414  ax-bndl 1415  ax-4 1416  ax-14 1421  ax-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038  ax-sep 3902  ax-pow 3954  ax-pr 3971
This theorem depends on definitions:  df-bi 114  df-3an 898  df-tru 1262  df-nf 1366  df-sb 1662  df-eu 1919  df-mo 1920  df-clab 2043  df-cleq 2049  df-clel 2052  df-nfc 2183  df-ral 2328  df-rex 2329  df-v 2576  df-sbc 2787  df-un 2949  df-in 2951  df-ss 2958  df-pw 3388  df-sn 3408  df-pr 3409  df-op 3411  df-uni 3608  df-br 3792  df-opab 3846  df-id 4057  df-xp 4378  df-rel 4379  df-cnv 4380  df-co 4381  df-dm 4382  df-rn 4383  df-res 4384  df-ima 4385  df-iota 4894  df-fun 4931  df-fn 4932  df-fv 4937
This theorem is referenced by:  supisolem  6411
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