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Theorem inegd 1414
Description: Negation introduction rule from natural deduction. (Contributed by Mario Carneiro, 9-Feb-2017.)
Hypothesis
Ref Expression
inegd.1 ((𝜑𝜓) → ⊥)
Assertion
Ref Expression
inegd (𝜑 → ¬ 𝜓)

Proof of Theorem inegd
StepHypRef Expression
1 inegd.1 . . 3 ((𝜑𝜓) → ⊥)
21ex 115 . 2 (𝜑 → (𝜓 → ⊥))
3 dfnot 1413 . 2 𝜓 ↔ (𝜓 → ⊥))
42, 3sylibr 134 1 (𝜑 → ¬ 𝜓)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  wfal 1400
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 617  ax-in2 618
This theorem depends on definitions:  df-bi 117  df-tru 1398  df-fal 1401
This theorem is referenced by:  genpdisj  7721  cauappcvgprlemdisj  7849  caucvgprlemdisj  7872  caucvgprprlemdisj  7900  suplocexprlemdisj  7918  suplocexprlemub  7921  suplocsrlem  8006  resqrexlemgt0  11547  resqrexlemoverl  11548  leabs  11601  climge0  11852  isprm5lem  12679  ennnfonelemex  13001  dedekindeu  15313  dedekindicclemicc  15322  pw1nct  16456
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