NFE Home New Foundations Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  NFE Home  >  Th. List  >  pm3.37 GIF version

Theorem pm3.37 562
Description: Theorem *3.37 (Transp) of [WhiteheadRussell] p. 112. (Contributed by NM, 3-Jan-2005.) (Proof shortened by Wolf Lammen, 23-Oct-2012.)
Assertion
Ref Expression
pm3.37 (((φ ψ) → χ) → ((φ ¬ χ) → ¬ ψ))

Proof of Theorem pm3.37
StepHypRef Expression
1 pm4.14 561 . 2 (((φ ψ) → χ) ↔ ((φ ¬ χ) → ¬ ψ))
21biimpi 186 1 (((φ ψ) → χ) → ((φ ¬ χ) → ¬ ψ))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4   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)
  Copyright terms: Public domain W3C validator