/** :  "Send more money" is a well-known puzzle. Each of the letters
    D,E,M,N,O,R,S and Y represents a different digit. Moreover, when each
    letter is mapped to its corresponding digit the equation SEND + MORE =
    MONEY holds. Below is a very naive . 
    Since there are 8 letters to be
    solved, it simply explore the 10*9*...*3 mappings of letters to
    digits.
*/

solvSlow( [D,E,M,N,O,R,S,Y]) :-
	Lst = [S,E,N,D,M,O,R,Y],
	Digits = [0,1,2,3,4,5,6,7,8,9],
	assign_digits(Lst, Digits),
	1000*S + 100*E + 10*N + D +
	1000*M + 100*O + 10*R + E =:=
	10000*M + 1000*O + 100*N + 10*E + Y,
	write(Lst).


assign_digits([], _List).
assign_digits([D|Ds], List):-
        select(D, List, NewList),
        assign_digits(Ds, NewList).