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Theorem iseqsetvlem 2828
Description: Lemma for iseqsetv-cleq 2829. (Contributed by Wolf Lammen, 17-Aug-2025.) (Proof modification is discouraged.)
Assertion
Ref Expression
iseqsetvlem (∃𝑥 𝑥 = 𝐴 ↔ ∃𝑧 𝑧 = 𝐴)
Distinct variable group:   𝑥,𝑧,𝐴

Proof of Theorem iseqsetvlem
StepHypRef Expression
1 eqeq1 2769 . 2 (𝑥 = 𝑧 → (𝑥 = 𝐴𝑧 = 𝐴))
21cbvexvw 2070 1 (∃𝑥 𝑥 = 𝐴 ↔ ∃𝑧 𝑧 = 𝐴)
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  wb 209   = wceq 1570  wex 1812
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-9 2156  ax-ext 2737
This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1813  df-cleq 2757
This theorem is used by:  iseqsetv-cleq  2829
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