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Theorem pm5.3 692
Description: Theorem *5.3 of [WhiteheadRussell] p. 125. (Contributed by NM, 3-Jan-2005.) (Proof shortened by Andrew Salmon, 7-May-2011.)
Assertion
Ref Expression
pm5.3 (((φ ψ) → χ) ↔ ((φ ψ) → (φ χ)))

Proof of Theorem pm5.3
StepHypRef Expression
1 impexp 433 . 2 (((φ ψ) → χ) ↔ (φ → (ψχ)))
2 imdistan 670 . 2 ((φ → (ψχ)) ↔ ((φ ψ) → (φ χ)))
31, 2bitri 240 1 (((φ ψ) → χ) ↔ ((φ ψ) → (φ χ)))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 176   wa 358
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This theorem depends on definitions:  df-bi 177  df-an 360
This theorem is referenced by: (None)
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