如何在序言中创建结果列表？

Question

I did write a cost calculator, the costs can be more than one value of same inputs so I need to find minimum cost. The calculator is running corrently, but I couldn't do put into a list and find the minumum value of the list, how can I do it? This is my calculator,

cal(X,Y,CLIST) :- calcualtor(X,Y,C).
calcualtor(X,Y,C ) :- calculate_cost(X,Z,A), calcualtor(Z,Y,B),C is A+B.
calcualtor(X,Y,C) :-  calculate_cost(X,Y,C).

When I call cal(A,B,X) it gives X = 7 then when I press ";" it gives X = 5 then when I press ";" it gives X = 14 etc.

I want to [7,5,14,..] then find the min value of the list.

Note: I can't use swi library functions

Answer 1

Why do you need a list ? You're looking for the minimum. That is, look for a value that does not have another greater that it. The explicit negation - called \\+ - is key to force Prolog to evaluate alternative bindings.