NFE Home New Foundations Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  NFE Home  >  Th. List  >  pm2.6 GIF version

Theorem pm2.6 162
Description: Theorem *2.6 of [WhiteheadRussell] p. 107. (Contributed by NM, 3-Jan-2005.)
Assertion
Ref Expression
pm2.6 ((¬ φψ) → ((φψ) → ψ))

Proof of Theorem pm2.6
StepHypRef Expression
1 id 19 . 2 ((¬ φψ) → (¬ φψ))
2 idd 21 . 2 ((¬ φψ) → (ψψ))
31, 2jad 154 1 ((¬ φψ) → ((φψ) → ψ))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This theorem is referenced by:  pm2.61  163
  Copyright terms: Public domain W3C validator