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Theorem reueq1f 2497
 Description: Equality theorem for restricted uniqueness quantifier, with bound-variable hypotheses instead of distinct variable restrictions. (Contributed by NM, 5-Apr-2004.) (Revised by Andrew Salmon, 11-Jul-2011.)
Hypotheses
Ref Expression
raleq1f.1 xA
raleq1f.2 xB
Assertion
Ref Expression
reueq1f (A = B → (∃!x A φ∃!x B φ))

Proof of Theorem reueq1f
StepHypRef Expression
1 raleq1f.1 . . . 4 xA
2 raleq1f.2 . . . 4 xB
31, 2nfeq 2182 . . 3 x A = B
4 eleq2 2098 . . . 4 (A = B → (x Ax B))
54anbi1d 438 . . 3 (A = B → ((x A φ) ↔ (x B φ)))
63, 5eubid 1904 . 2 (A = B → (∃!x(x A φ) ↔ ∃!x(x B φ)))
7 df-reu 2307 . 2 (∃!x A φ∃!x(x A φ))
8 df-reu 2307 . 2 (∃!x B φ∃!x(x B φ))
96, 7, 83bitr4g 212 1 (A = B → (∃!x A φ∃!x B φ))
 Colors of variables: wff set class Syntax hints:   → wi 4   ∧ wa 97   ↔ wb 98   = wceq 1242   ∈ wcel 1390  ∃!weu 1897  Ⅎwnfc 2162  ∃!wreu 2302 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 629  ax-5 1333  ax-7 1334  ax-gen 1335  ax-ie1 1379  ax-ie2 1380  ax-8 1392  ax-10 1393  ax-11 1394  ax-i12 1395  ax-bndl 1396  ax-4 1397  ax-17 1416  ax-i9 1420  ax-ial 1424  ax-i5r 1425  ax-ext 2019 This theorem depends on definitions:  df-bi 110  df-tru 1245  df-nf 1347  df-sb 1643  df-eu 1900  df-cleq 2030  df-clel 2033  df-nfc 2164  df-reu 2307 This theorem is referenced by:  reueq1  2501
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