/* Fractions problem in Picat. 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 See also my Picat page: http://www.hakank.org/picat/ */ import cp. main => go. go ?=> fractions(Digits), writeln(Digits), fail. go => true. fractions(Digits) => Digits = [A,B,C,D,E,F,G,H,I], Digits :: 1..9, all_different(Digits), DD = [D1,D2,D3], DD :: 1..81, D1 #= 10*B+C, D2 #= 10*E+F, D3 #= 10*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 solve([ffc,split],Digits).