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Theorem sylnib 611
Description: A mixed syllogism inference from an implication and a biconditional. (Contributed by Wolf Lammen, 16-Dec-2013.)
Hypotheses
Ref Expression
sylnib.1 (𝜑 → ¬ 𝜓)
sylnib.2 (𝜓𝜒)
Assertion
Ref Expression
sylnib (𝜑 → ¬ 𝜒)

Proof of Theorem sylnib
StepHypRef Expression
1 sylnib.1 . 2 (𝜑 → ¬ 𝜓)
2 sylnib.2 . . 3 (𝜓𝜒)
32a1i 9 . 2 (𝜑 → (𝜓𝜒))
41, 3mtbid 607 1 (𝜑 → ¬ 𝜒)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wb 102
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-in1 554  ax-in2 555
This theorem depends on definitions:  df-bi 114
This theorem is referenced by:  sylnibr  612  ssnelpss  3316  inssdif0im  3318  ordtriexmidlem2  4273  dmsn0el  4817  fidifsnen  6361  ltpopr  6750  caucvgprprlemnbj  6848  xrlttri3  8818  fzneuz  9064
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