Hệ chuyên gia LPNchapter2

Lecture 2© Patrick Blackburn, Johan Bos & Kristina Striegnitz•  Theory.–  Unification.–  Unification in Prolog.–  Proof search•  Exercises.–  Exercises of LPN chapter 2.–  Practical of this lecture© Patrick Blackburn, Johan Bos & Kristina Striegnitz•  Discuss unification in Prolog.–  Show how Prolog unification differs unification•  Explain Prolog’s search strategy.–  Prolog deduces new information from old,.using modus © Patrick Blackburn, Johan Bos & Kristina Striegnitz•  Recall the previous example, where that Prolog (X).(mia).thereby instantiating the variable X atom miaRecall Prolog Terms© Patrick Blackburn, Johan Bos & Kristina StriegnitzTermsSimple © Patrick Blackburn, Johan Bos & Kristina Striegnitz•  Working definition – two terms unify:.•  if they are the same term, or.•  if they contain variables that can be with terms in such a way that terms are equal. | Lecture 2 © Patrick Blackburn, Johan Bos & Kristina Striegnitz •  Theory –  Unification –  Unification in Prolog –  Proof search •  Exercises –  Exercises of LPN chapter 2 –  Practical work Aim of this lecture © Patrick Blackburn, Johan Bos & Kristina Striegnitz •  Discuss unification in Prolog –  Show how Prolog unification differs from standard unification •  Explain Prolog’s search strategy –  Prolog deduces new information from old, using modus ponens Unification © Patrick Blackburn, Johan Bos & Kristina Striegnitz •  Recall the previous example, where we said that Prolog unifies woman(X) with woman(mia) thereby instantiating the variable X with the atom mia. Recall Prolog Terms © Patrick Blackburn, Johan Bos & Kristina Striegnitz Terms Simple Terms Constants Atoms Variables Numbers Complex Terms Unification © Patrick Blackburn, Johan Bos & Kristina Striegnitz •  Working definition – two terms unify: •  if they are the same term, or •  if they contain variables that can be uniformly instantiated with terms in such a way that the resulting terms are .