a(A,B) :- B is asin(A).

fit(Points,A,B,C,D) :-
	value(A), value(B), value(C), value(D), fitpoints(Points,A,B,C,D),!.

value(1).
value(2).
value(0.5).
fitpoints([],_,_,_,_).
fitpoints([[X,Y]|Points],A,B,C,D) :-
	fit(X,Y,A,B,C,D), fitpoints(Points,A,B,C,D).
fit(X,Y,A,B,C,D) :- Y1 is A*sin(B*X)+C*sin(D*X), Y-0.01<Y1, Y1<Y+0.01.