Solution to the problem WWWDOT - GOOGLE = DOTCOM (GLAT question 1) in prolog

google_glat_q1.pro

% solution to the problem WWWDOT - GOOGLE = DOTCOM in prolog
carry(0).
carry(1).

digit(A) :- carry(A).
digit(2).
digit(3).
digit(4).
digit(5).
digit(6).
digit(7).
digit(8).
digit(9).

solve(W,D,O,T,G,L,E,C,M):-
    carry(ALPHA),
    carry(BETA),
    carry(GAMMA),
    carry(DELTA),
    carry(EPSILON),
    digit(T),
    digit(E),
    T \== E,
    digit(M),
    T \== M,
    E \== M,
    (T+10*ALPHA) - E =:= M,
    digit(O),
    T \== O,
    E \== O,
    M \== O,
    digit(L),
    T \== L,
    E \== L,
    M \== L,
    O \== L,
    (O-ALPHA+10*BETA) - L =:= O,
    digit(W),
    T \== W,
    E \== W,
    M \== W,
    O \== W,
    L \== W,
    (W-GAMMA+10*DELTA) - O =:= T,
    (W-DELTA+10*EPSILON) - O =:= O,
    digit(D),
    T \== D,
    E \== D,
    M \== D,
    O \== D,
    L \== D,
    W \== D,
    digit(G),
    T \== G,
    E \== G,
    M \== G,
    O \== G,
    L \== G,
    W \== G,
    D \== G,
    digit(C),
    T \== C,
    E \== C,
    M \== C,
    O \== C,
    L \== C,
    W \== C,
    D \== C,
    G \== C,
    (D-BETA+10*GAMMA) - G =:= C,
    (W-EPSILON) - G =:= D.