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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  7485  cauappcvgprlemdisj  7613  caucvgprlemdisj  7636  caucvgprprlemdisj  7664  suplocexprlemdisj  7682  suplocexprlemub  7685  suplocsrlem  7770  resqrexlemgt0  10984  resqrexlemoverl  10985  leabs  11038  climge0  11288  isprm5lem  12095  ennnfonelemex  12369  dedekindeu  13395  dedekindicclemicc  13404  pw1nct  14036
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