Work Note 17, DM509, fall 2008

Exercises December 9 (S1) and 10 (S2)

• Some Prolog repetition problems:
  • Define listlen(L,N) to succeed if L is a list of length N.
  • Define lastone(X,L) to succeed if X is the last element in the list L.
  • Define sublist(L1,L2) to succeed if L1 is a sublist of L2, i.e., the elements in L1 must also be consecutive in L2.
  • Consider the statement

    Some people like other people who do not like anyone.

    This can be formalized as

    ∃X(p(X)∧∃Y(p(Y)∧likes(X,Y)∧∀Z(p(Z)⇒¬likes(Y,Z)))).

    Convert this to clausal form.
• Work sheet.
• [H07] exercises 6.1, 6.4, 6.5, 6.6, 7.1, 7.2.