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Theorem imnani 412
Description: Express implication in terms of conjunction. (Contributed by Mario Carneiro, 28-Sep-2015.)
Hypothesis
Ref Expression
imnani.1 ¬ (φ ψ)
Assertion
Ref Expression
imnani (φ → ¬ ψ)

Proof of Theorem imnani
StepHypRef Expression
1 imnani.1 . 2 ¬ (φ ψ)
2 imnan 411 . 2 ((φ → ¬ ψ) ↔ ¬ (φ ψ))
31, 2mpbir 200 1 (φ → ¬ 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:  mpto1  1533  eueq3  3012
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