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Theorem r19.32 44477
Description: Theorem 19.32 of [Margaris] p. 90 with restricted quantifiers, analogous to r19.32v 3267. (Contributed by Alexander van der Vekens, 29-Jun-2017.)
Hypothesis
Ref Expression
r19.32.1 𝑥𝜑
Assertion
Ref Expression
r19.32 (∀𝑥𝐴 (𝜑𝜓) ↔ (𝜑 ∨ ∀𝑥𝐴 𝜓))

Proof of Theorem r19.32
StepHypRef Expression
1 r19.32.1 . . . 4 𝑥𝜑
21nfn 1861 . . 3 𝑥 ¬ 𝜑
32r19.21 3138 . 2 (∀𝑥𝐴𝜑𝜓) ↔ (¬ 𝜑 → ∀𝑥𝐴 𝜓))
4 df-or 844 . . 3 ((𝜑𝜓) ↔ (¬ 𝜑𝜓))
54ralbii 3090 . 2 (∀𝑥𝐴 (𝜑𝜓) ↔ ∀𝑥𝐴𝜑𝜓))
6 df-or 844 . 2 ((𝜑 ∨ ∀𝑥𝐴 𝜓) ↔ (¬ 𝜑 → ∀𝑥𝐴 𝜓))
73, 5, 63bitr4i 302 1 (∀𝑥𝐴 (𝜑𝜓) ↔ (𝜑 ∨ ∀𝑥𝐴 𝜓))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wb 205  wo 843  wnf 1787  wral 3063
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1799  ax-4 1813  ax-5 1914  ax-6 1972  ax-7 2012  ax-12 2173
This theorem depends on definitions:  df-bi 206  df-or 844  df-ex 1784  df-nf 1788  df-ral 3068
This theorem is referenced by:  2reu3  44489
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