Name ___________________________________________________
5 pages of handwritten notes allowed.
1. Prove that the sets {∨, ¬} and {→, ¬} are
sufficient, i.e., that all other propositional connectives can
be described in terms of these connectives.
2. Use natural deduction to prove that ¬ p → q |− p
∨ q. Hint: use an axiom a ∨ ¬ a for an
appropriate a.
3. Use resolution to prove that ¬ p → q |− p ∨
q.
4. Use truth tables to prove that ¬ p → q |− p ∨
q.
5-6. Use program synthesis to solve the following problem. For an
electric circuit, the voltage V, resistance R, current I, and
power P are related by the following formulas: V = I * R (Ohm's
Law) and P = V * I. Suppose that we know the voltage V = 110 V and
the power P, and we need to estimate the resistance R. Use the
wave algorithm to synthesize the program. Then show how a similar
program can be synthesized by using Prolog.
7-8. Use resolution to prove that if we have ∀x (Ax →
Bx) and ∃x (Ax ∧ Cx), then ∃x (Bx ∧ Cx). Prove
the same statement by using natural deduction.
9. Use the predicates C(x) (x is a cat), L(x, y) (x likes y), and
P(x, y) (x likes to plays with y) to translate the following
statements into predicate logic:
Cats like to play with
other cats.
Some cats do not like to play.
Some cats only
play with those they like.
10. Suppose that we have Prolog predicates parent(P, C), male(X),
and female(X). Write down Prolog rules that describe
grandfather(GF, X) and grandson(GS, X) in these terms. Give an
example of using these rules.