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Theorem r19.15 1292
Description: Distribute a restricted universal quantifier over a biconditional. Theorem 19.15 of [Margaris] p. 90 with restricted quantification.
Assertion
Ref Expression
r19.15 (∀xA (φψ) → (∀xA φ ↔ ∀xA ψ))

Proof of Theorem r19.15
StepHypRef Expression
1 hbra1 1237 . . 3 (∀xA (φψ) → ∀xxA (φψ))
2 id 9 . . 3 (∀xA (φψ) → ∀xA (φψ))
31, 219.21ai 740 . 2 (∀xA (φψ) → ∀xxA (φψ))
4 ra4 1243 . . 3 (∀xA (φψ) → (xA → (φψ)))
54imp 277 . 2 ((∀xA (φψ) ∧ xA) → (φψ))
63, 5biralda 1213 1 (∀xA (φψ) → (∀xA φ ↔ ∀xA ψ))
Colors of variables: wff set class
Syntax hints:   → wi 2   ↔ wb 127   ∈ wcel 1092  ∀wral 1201
This theorem is referenced by:  isowe 2941  rankonid 3538  kmlem12 3591  kmlem13 3592
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-gen 677
This theorem depends on definitions:  df-bi 128  df-an 198  df-ral 1205
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