Introduction to
Logic Programming
What
versus
How
Exercise 7.1 - Syntax
Say whether each of the following expressions is a syntactically legal view definition.
a.
r(X,Y) :- p(X,Y) & q()
legal
illegal
b.
r(X,Y) :- p(X,Y) & ~q(Y,X)
legal
illegal
c.
~r(X,Y) :- p(X,Y) & q(Y,X)
legal
illegal
d.
p(X,Y) & q(Y,X) :- r(X,Y)
legal
illegal
e.
p(X,Y) & ~q(Y,X) :- r(X,Y)
legal
illegal