CS472/572
INTRODUCTION TO ARTIFICIAL INTELLIGENCE
Spring, 1996
HOMEWORK 3
Due: In Lecture, Friday, March 8, 1996.
(6) Use truth tables to show that the following sentences are valid,
and thus that the equivalences hold. [Text, Exercise 6.2, p. 180]
(P => Q) <=> (~P v Q)
~(P & Q) <=> (~P v ~Q)
P & (Q v R) <=> (P & Q) v (P & R)
Consider Exercise 6.5 of the text (p. 181).
(3) Choose atomic propositions to use to represent the information in
this exercise, and give the intensional semantics of those
atomic propositions.
(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.