Exercise 6.2 - Redundant Subgoal Deletion

Introduction to
Logic Programming

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Exercise 6.2 - Redundant Subgoal Deletion

For each of the following groups of query rules, select the alternative that is equivalent to the first rule in the group.

	(a)	`goal(X) :- p(X,Y) & q(Y) & q(Z)`
		`goal(X) :- p(X,Y)`
		`goal(X) :- p(X,Y) & q(Y)`
		`goal(X) :- p(X,Y) & q(Z)`

	(b)	`goal(X) :- p(X) & q(Z) & q(W)`
		`goal(X) :- p(X)`
		`goal(X) :- p(X) & q(X)`
		`goal(X) :- p(X) & q(W)`

	(c)	`goal(X,Y,Z) :- p(X,Y) & q(Y) & q(Z) & q(W)`
		`goal(X,Y,Z) :- p(X,Y) & q(Y) & q(Z)`
		`goal(X,Y,Z) :- p(X,Y) & q(Y) & q(W)`
		`goal(X,Y,Z) :- p(X,Y) & q(Z) & q(W)`