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Theorem inegd 1391
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 1390 . 2 𝜓 ↔ (𝜓 → ⊥))
42, 3sylibr 134 1 (𝜑 → ¬ 𝜓)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  wfal 1377
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 615  ax-in2 616
This theorem depends on definitions:  df-bi 117  df-tru 1375  df-fal 1378
This theorem is referenced by:  genpdisj  7635  cauappcvgprlemdisj  7763  caucvgprlemdisj  7786  caucvgprprlemdisj  7814  suplocexprlemdisj  7832  suplocexprlemub  7835  suplocsrlem  7920  resqrexlemgt0  11302  resqrexlemoverl  11303  leabs  11356  climge0  11607  isprm5lem  12434  ennnfonelemex  12756  dedekindeu  15066  dedekindicclemicc  15075  pw1nct  15902
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