Small prolog Program

I had a small code that I wrote for the program I don't know if you want to use it or not. its a very small code not a big one. small(X) :- X < 50. medium(X) :- X >= 50, X =< 100. big(X) :- X > 100. % classify(+N, ?Classification) classify(N, small) :- ...guard...test N for smallness... classify(N, medium) :- ...guard...test N for mediumness... classify(N, big) :- ...guard...test N for bigness... classify(N, small) :- must_be(number,N), N < 50, !. classify(N, medium) :- must_be(number,N), N >= 50, N =< 100, !. classify(N, big) :- must_be(number,N), N > 100.