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Theorem biralda 1213
Description: Formula-building rule for restricted universal quantifier (deduction rule).
Hypotheses
Ref Expression
biralda.1 (φ → ∀xφ)
biralda.2 ((φxA) → (ψχ))
Assertion
Ref Expression
biralda (φ → (∀xA ψ ↔ ∀xA χ))

Proof of Theorem biralda
StepHypRef Expression
1 biralda.1 . . 3 (φ → ∀xφ)
2 biralda.2 . . . . 5 ((φxA) → (ψχ))
32exp 291 . . . 4 (φ → (xA → (ψχ)))
43pm5.74d 444 . . 3 (φ → ((xAψ) ↔ (xAχ)))
51, 4biald 782 . 2 (φ → (∀x(xAψ) ↔ ∀x(xAχ)))
6 df-ral 1205 . 2 (∀xA ψ ↔ ∀x(xAψ))
7 df-ral 1205 . 2 (∀xA χ ↔ ∀x(xAχ))
85, 6, 73bitr4g 428 1 (φ → (∀xA ψ ↔ ∀xA χ))
Colors of variables: wff set class
Syntax hints:   → wi 2   ↔ wb 127   ∧ wa 196  ∀wal 672   ∈ wcel 1092  ∀wral 1201
This theorem is referenced by:  biraldva 1215  birald 1217  bi2ralda 1232  r19.15 1292  iineq2 2007  mapxpen 3390  xpmapenlem5 3395
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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