1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | /* Fractions problem in B-Prolog. Prolog benchmark problem (BProlog) """ Find distinct non-zero digits such that the following equation holds: A D G ------ + ----- + ------ = 1 B*C E*F H*I """ Model created by Hakan Kjellerstrand, hakank@gmail.com*/% Licenced under CC-BY-4.0 : http://creativecommons.org/licenses/by/4.0/go :- fractions(Digits), writeln(Digits), fail.fractions(Digits) :- Digits = [A,B,C,D,E,F,G,H,I], Digits :: 1..9, alldifferent(Digits), DD = [D1,D2,D3], DD :: 1..81, D1 #= B*C, D2 #= E*F, D3 #= H*I, A*D2*D3 + D*D1*D3 + G*D1*D2 #= D1*D2*D3, % break the symmetry A*D2 #>= D*D1, D*D3 #>= G*D2, %redundant constraints 3*A #>= D1, 3*G #=< D2, % search term_variables([Digits],Vars), labeling([ffc,split],Vars). |