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Theorem orcanai 879
Description: Change disjunction in consequent to conjunction in antecedent. (Contributed by NM, 8-Jun-1994.)
Hypothesis
Ref Expression
orcanai.1 (φ → (ψ χ))
Assertion
Ref Expression
orcanai ((φ ¬ ψ) → χ)

Proof of Theorem orcanai
StepHypRef Expression
1 orcanai.1 . . 3 (φ → (ψ χ))
21ord 366 . 2 (φ → (¬ ψχ))
32imp 418 1 ((φ ¬ ψ) → χ)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4   wo 357   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-or 359  df-an 360
This theorem is referenced by: (None)
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