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Theorem inegd 1367
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 114 . 2 (𝜑 → (𝜓 → ⊥))
3 dfnot 1366 . 2 𝜓 ↔ (𝜓 → ⊥))
42, 3sylibr 133 1 (𝜑 → ¬ 𝜓)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 103  wfal 1353
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 609  ax-in2 610
This theorem depends on definitions:  df-bi 116  df-tru 1351  df-fal 1354
This theorem is referenced by:  genpdisj  7472  cauappcvgprlemdisj  7600  caucvgprlemdisj  7623  caucvgprprlemdisj  7651  suplocexprlemdisj  7669  suplocexprlemub  7672  suplocsrlem  7757  resqrexlemgt0  10971  resqrexlemoverl  10972  leabs  11025  climge0  11275  isprm5lem  12082  ennnfonelemex  12356  dedekindeu  13354  dedekindicclemicc  13363  pw1nct  13996
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