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Theorem mtand 655
Description: A modus tollens deduction. (Contributed by Jeff Hankins, 19-Aug-2009.)
Hypotheses
Ref Expression
mtand.1 (𝜑 → ¬ 𝜒)
mtand.2 ((𝜑𝜓) → 𝜒)
Assertion
Ref Expression
mtand (𝜑 → ¬ 𝜓)

Proof of Theorem mtand
StepHypRef Expression
1 mtand.1 . 2 (𝜑 → ¬ 𝜒)
2 mtand.2 . . 3 ((𝜑𝜓) → 𝜒)
32ex 114 . 2 (𝜑 → (𝜓𝜒))
41, 3mtod 653 1 (𝜑 → ¬ 𝜓)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 103
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia3 107  ax-in1 604  ax-in2 605
This theorem is referenced by:  frirrg  4328  phpm  6831  diffisn  6859  tridc  6865  nnnninfeq  7092  pm54.43  7146  addcanprleml  7555  addcanprlemu  7556  iseqf1olemklt  10420  isprm5lem  12073  pw2dvdseulemle  12099  sqne2sq  12109  pythagtriplem4  12200  pythagtriplem11  12206  pythagtriplem13  12208  ctinfomlemom  12360  ivthinc  13261  pwle2  13878
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