CS472/572 INTRODUCTION TO ARTIFICIAL INTELLIGENCE Spring, 1996

HOMEWORK 3
Due: In Lecture, Friday, March 8, 1996.

  1. (6) Use truth tables to show that the following sentences are valid, and thus that the equivalences hold. [Text, Exercise 6.2, p. 180]
    1. (P => Q) <=> (~P v Q)
    2. ~(P & Q) <=> (~P v ~Q)
    3. P & (Q v R) <=> (P & Q) v (P & R)

  2. Consider Exercise 6.5 of the text (p. 181).
    1. (3) Choose atomic propositions to use to represent the information in this exercise, and give the intensional semantics of those atomic propositions.
    2. (6) The text asks if you can prove that the unicorn is mythical, magical and/or horned. For each one of these three that you can prove, give the Fitch-style proof. For each one that you cannot prove, provide a falsifying assignment of truth values to the atomic propositions. In all cases, use the representation of atomic propositions you chose above.

Back to CS4/572 Syllabus.
Stuart C. Shapiro <shapiro@cs.buffalo.edu>
Thu Jan 25 16:32:27 EST 1996