This exercise looks into the relationship between clauses and implication sentences.

a. Show that the clause (—P1 V . . . V —Pm VQ) iS logically equivalent to the implication sentence (P1 Λ . . . Λ Pm) Q.

b. Show that every clause (regardless of the number of positive literals) can be written in the form (P1 Λ. . . Λ Pm) (Q1 V . V Qn), where the Ps and Qs are proposition symbols A knowledge base consisting of such sentences IS in implicative normal form or Kowalski form.

c. Write down the full resolution rule for sentences in implicative normal form.