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Theorem inegd 1383
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 1382 . 2 𝜓 ↔ (𝜓 → ⊥))
42, 3sylibr 134 1 (𝜑 → ¬ 𝜓)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  wfal 1369
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 1367  df-fal 1370
This theorem is referenced by:  genpdisj  7552  cauappcvgprlemdisj  7680  caucvgprlemdisj  7703  caucvgprprlemdisj  7731  suplocexprlemdisj  7749  suplocexprlemub  7752  suplocsrlem  7837  resqrexlemgt0  11061  resqrexlemoverl  11062  leabs  11115  climge0  11365  isprm5lem  12173  ennnfonelemex  12465  dedekindeu  14558  dedekindicclemicc  14567  pw1nct  15211
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