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Theorem cbv3 1630
Description: Rule used to change bound variables, using implicit substitution. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Wolf Lammen, 12-May-2018.)
Hypotheses
Ref Expression
cbv3.1 𝑦𝜑
cbv3.2 𝑥𝜓
cbv3.3 (𝑥 = 𝑦 → (𝜑𝜓))
Assertion
Ref Expression
cbv3 (∀𝑥𝜑 → ∀𝑦𝜓)

Proof of Theorem cbv3
StepHypRef Expression
1 cbv3.1 . . 3 𝑦𝜑
21nfal 1468 . 2 𝑦𝑥𝜑
3 cbv3.2 . . 3 𝑥𝜓
4 cbv3.3 . . 3 (𝑥 = 𝑦 → (𝜑𝜓))
53, 4spim 1626 . 2 (∀𝑥𝜑𝜓)
62, 5alrimi 1415 1 (∀𝑥𝜑 → ∀𝑦𝜓)
Colors of variables: wff set class
Syntax hints:  wi 4  wal 1241  wnf 1349
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-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-4 1400  ax-i9 1423  ax-ial 1427
This theorem depends on definitions:  df-bi 110  df-nf 1350
This theorem is referenced by:  cbv3h  1631  cbv1  1632  mo2n  1928  mo23  1941  setindis  10092  bdsetindis  10094
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