ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  inegd GIF version

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  7636  cauappcvgprlemdisj  7764  caucvgprlemdisj  7787  caucvgprprlemdisj  7815  suplocexprlemdisj  7833  suplocexprlemub  7836  suplocsrlem  7921  resqrexlemgt0  11331  resqrexlemoverl  11332  leabs  11385  climge0  11636  isprm5lem  12463  ennnfonelemex  12785  dedekindeu  15095  dedekindicclemicc  15104  pw1nct  15940
  Copyright terms: Public domain W3C validator