Prolog "or" operator, query?

Question

I'm working on some prolog that I'm new to. I'm looking for an "or" operator registered(X, Y), Y=ct101, Y=ct102, Y=ct103. Here's my query. What I want to write is code that will: "return X, given that Y is equal to value Z OR value Q OR value P" I'm asking it to return X if Y is equal to all 3 though. What's the or operator here? Is there one?

Answer 1

the following might be helpful:

here's a prolog file:

a(B) :- B = abc.

a(B) :- B = def.

a(B) :- B = ghi.

after consulting that file,

here's some interactions:

?- a(X).

X = abc ;

X = def ;

X = ghi.

the file says "a(B)" implies either B equals abc or def or ghi.

in the interactions area, i typed "a(X).". this is like asking prolog "what would make 'a(X) true?". and prolog responds "that would be true if X is abc".

and then i typed ';' which is like saying "what other answers are there?" and then prolog replies "that would also be true if X is def".

and finally, prolog tells me that 'a(X)' is true if X is ghi.