Inference

• Inference -

  Determining conclusions logically entailed by premises
  

• Patterns of inference represented as inference rules

• Example inference rules -

  Modus Ponens Modus Tollens
  
  (=> S1 S2), S1 (=> S1 S2), (not S2)
  -------- ----------
  S2 (not S1)

• An inference rule can be verified using a truth table

  S1 S2 (not S1) (not S2) (=> S1 S2)
  
  ———————————————————————————
  True True False False True
  True False False True False
  False True True False True
  False False True True True

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