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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  7733  cauappcvgprlemdisj  7861  caucvgprlemdisj  7884  caucvgprprlemdisj  7912  suplocexprlemdisj  7930  suplocexprlemub  7933  suplocsrlem  8018  resqrexlemgt0  11571  resqrexlemoverl  11572  leabs  11625  climge0  11876  isprm5lem  12703  ennnfonelemex  13025  dedekindeu  15337  dedekindicclemicc  15346  usgr1vr  16087  pw1nct  16540
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