Prolog Four Winns game

gistfile1.txt

:- dynamic state/3.
:- dynamic top/2.


top(0,0).

play(Color, Col) :-
	top(Col, Row), assert(state(Col, Row, Color)),
	Next is Row + 1, retract(top(Col, Row)), assert(top(Col, Next)).

win(X,Y, Winner) :-
	state(X,Y, Color), N1 is Y - 1, state(X, N1, Color), N2 is N1 - 1, state(X,N2, Color), N3 is N2 - 1, state(X, N3, Color), Winner = Color.

win(X,Y, Winner) :-
	state(X,Y, Color), N1 is X - 1, state(N1, Y, Color), N2 is N1 - 1, state(N2, Y, Color), N3 is N2 - 1, state(N3, Y, Color), Winner = Color.

win(X,Y, Winner) :-
	state(X,Y, Color),
	N1 is X + 1, M1 is Y + 1, state(N1, M1, Color),
	N2 is N1 + 1, M2 is M1 + 1, state(N2, M2, Color),
	N3 is N2 + 1, M3 is M2 + 1, state(N3, M3, Color),
	Winner = Color.

win(X,Y, Winner) :-
	state(X,Y, Color),
	N1 is X + 1, M1 is Y - 1, state(N1, M1, Color),
	N2 is N1 + 1, M2 is M1 - 1, state(N2, M2, Color),
	N3 is N2 + 1, M3 is M2 - 1, state(N3, M3, Color),
	Winner = Color.