／var／logmarcus chiu

Monotonic／Admissible - Non-Monotonic／Defeasible

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monotonicity and non-monotonicity are properties of Languages or Logic Classes

Monotonic Logic or Admissible Logic

  • a property of a formal logic language where the addition of any axioms to an existing theory T does not result in removal from the set of consequences of T
  • set of theorems of the system does not change when that rule is added to the existing rules of the system
  • requires all entailed sentences to remain entailed after new sentences are added to the KB. That is if KB |= α then KB ∧ β |= α
  • i.e. for all sets of sentences A and B: if (A ⊨ α) then (A,B ⊨ α) where α is a sentence

Non-Monotonic Logic or Defeasible Logic