DCP1172, Ch.8,9 1

Homework #3-1: predicate logic (20%)

• What is wrong with the following argument ?o Men are widely distributed over the earth.o Socrates is a man.o Therefore, Socrates is widely distributed over

the earth.• How should the facts represented by these

sentences be represented in logic so that this problem does not arise ?

DCP1172, Ch.8,9 2

Homework #3-2: Predicate logic (40%)

• Consider the following sentences:o John likes all kinds of food.o Apples are food.o Chicken is food.o Anything anyone eats and isn’t killed by is food.o Bill eats peanuts and is still alive.o Sue eats everything Bill eats.

a)Translate these sentences into formulas in predicate logic. (5%)

b)Prove that John likes peanuts using backward chaining. (15%)

c) Convert the formula of part a into clause form. (5%)d)Prove that John likes peanuts using resolution.

(15%)

DCP1172, Ch.8,9 3

Homework # 3-3 (40%) - Logic and Prolog programming

• Consider the following knowledge base: x y cat(x) ^ fish(y) LikesToEat(x,y) x calico(x) cat (x) x tuna(x) fish(x)tuna(Charlie)tuna(Herb)calico(Puss)

a) Convert these WFF’s into Horn clauses.b) Convert the Horn clauses into a PROLOG programc) Write a PROLOG query corresponding to the question,

“What does Puss like to eat? “ and show how it could be answered by your program.

d) Write another PROLOG program that corresponds to the same set of WFF’s but with a different answer to the same query.