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Theorem pm5.14 856
Description: Theorem *5.14 of [WhiteheadRussell] p. 123. (Contributed by NM, 3-Jan-2005.)
Assertion
Ref Expression
pm5.14 ((φψ) (ψχ))

Proof of Theorem pm5.14
StepHypRef Expression
1 ax-1 6 . . . 4 (ψ → (φψ))
21con3i 127 . . 3 (¬ (φψ) → ¬ ψ)
32pm2.21d 98 . 2 (¬ (φψ) → (ψχ))
43orri 365 1 ((φψ) (ψχ))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4   wo 357
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-or 359
This theorem is referenced by:  pm5.13  857
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