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Theorem inegd 1303
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 113 . 2 (𝜑 → (𝜓 → ⊥))
3 dfnot 1302 . 2 𝜓 ↔ (𝜓 → ⊥))
42, 3sylibr 132 1 (𝜑 → ¬ 𝜓)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 102  wfal 1289
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-in1 576  ax-in2 577
This theorem depends on definitions:  df-bi 115  df-tru 1287  df-fal 1290
This theorem is referenced by:  genpdisj  6713  cauappcvgprlemdisj  6841  caucvgprlemdisj  6864  caucvgprprlemdisj  6892  resqrexlemgt0  9906  resqrexlemoverl  9907  leabs  9960  climge0  10163
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