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Theorem inegd 1392
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 1391 . 2 𝜓 ↔ (𝜓 → ⊥))
42, 3sylibr 134 1 (𝜑 → ¬ 𝜓)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  wfal 1378
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 1376  df-fal 1379
This theorem is referenced by:  genpdisj  7671  cauappcvgprlemdisj  7799  caucvgprlemdisj  7822  caucvgprprlemdisj  7850  suplocexprlemdisj  7868  suplocexprlemub  7871  suplocsrlem  7956  resqrexlemgt0  11446  resqrexlemoverl  11447  leabs  11500  climge0  11751  isprm5lem  12578  ennnfonelemex  12900  dedekindeu  15210  dedekindicclemicc  15219  pw1nct  16142
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