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Theorem pm2.61 163
Description: Theorem *2.61 of [WhiteheadRussell] p. 107. Useful for eliminating an antecedent. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Wolf Lammen, 22-Sep-2013.)
Assertion
Ref Expression
pm2.61 ((φψ) → ((¬ φψ) → ψ))

Proof of Theorem pm2.61
StepHypRef Expression
1 pm2.6 162 . 2 ((¬ φψ) → ((φψ) → ψ))
21com12 27 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: (None)
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