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Theorem ceqsrexv 2696
Description: Elimination of a restricted existential quantifier, using implicit substitution. (Contributed by NM, 30-Apr-2004.)
Hypothesis
Ref Expression
ceqsrexv.1 (𝑥 = 𝐴 → (𝜑𝜓))
Assertion
Ref Expression
ceqsrexv (𝐴𝐵 → (∃𝑥𝐵 (𝑥 = 𝐴𝜑) ↔ 𝜓))
Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝜓,𝑥
Allowed substitution hint:   𝜑(𝑥)

Proof of Theorem ceqsrexv
StepHypRef Expression
1 df-rex 2329 . . 3 (∃𝑥𝐵 (𝑥 = 𝐴𝜑) ↔ ∃𝑥(𝑥𝐵 ∧ (𝑥 = 𝐴𝜑)))
2 an12 503 . . . 4 ((𝑥 = 𝐴 ∧ (𝑥𝐵𝜑)) ↔ (𝑥𝐵 ∧ (𝑥 = 𝐴𝜑)))
32exbii 1512 . . 3 (∃𝑥(𝑥 = 𝐴 ∧ (𝑥𝐵𝜑)) ↔ ∃𝑥(𝑥𝐵 ∧ (𝑥 = 𝐴𝜑)))
41, 3bitr4i 180 . 2 (∃𝑥𝐵 (𝑥 = 𝐴𝜑) ↔ ∃𝑥(𝑥 = 𝐴 ∧ (𝑥𝐵𝜑)))
5 eleq1 2116 . . . . 5 (𝑥 = 𝐴 → (𝑥𝐵𝐴𝐵))
6 ceqsrexv.1 . . . . 5 (𝑥 = 𝐴 → (𝜑𝜓))
75, 6anbi12d 450 . . . 4 (𝑥 = 𝐴 → ((𝑥𝐵𝜑) ↔ (𝐴𝐵𝜓)))
87ceqsexgv 2695 . . 3 (𝐴𝐵 → (∃𝑥(𝑥 = 𝐴 ∧ (𝑥𝐵𝜑)) ↔ (𝐴𝐵𝜓)))
98bianabs 553 . 2 (𝐴𝐵 → (∃𝑥(𝑥 = 𝐴 ∧ (𝑥𝐵𝜑)) ↔ 𝜓))
104, 9syl5bb 185 1 (𝐴𝐵 → (∃𝑥𝐵 (𝑥 = 𝐴𝜑) ↔ 𝜓))
Colors of variables: wff set class
Syntax hints:  wi 4  wa 101  wb 102   = wceq 1259  wex 1397  wcel 1409  wrex 2324
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-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038
This theorem depends on definitions:  df-bi 114  df-tru 1262  df-nf 1366  df-sb 1662  df-clab 2043  df-cleq 2049  df-clel 2052  df-nfc 2183  df-rex 2329  df-v 2576
This theorem is referenced by:  ceqsrexbv  2697  ceqsrex2v  2698  f1oiso  5492  creur  7986  creui  7987
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