Prolog, find minimum in a list

Question

in short: How to find min value in a list? (thanks for the advise kaarel)

long story:

I have created a weighted graph in amzi prolog and given 2 nodes, I am

Answer 1

%Usage: minl(List, Minimum).
minl([Only], Only).
minl([Head|Tail], Minimum) :-
    minl(Tail, TailMin),
    Minimum is min(Head, TailMin). 

The second rule does the recursion, in english "get the smallest value in the tail, and set Minimum to the smaller of that and the head". The first rule is the base case, "the minimum value of a list of one, is the only value in the list".

Test:

| ?- minl([2,4,1],1).

true ? 

yes
| ?- minl([2,4,1],X).

X = 1 ? 

yes

You can use it to check a value in the first case, or you can have prolog compute the value in the second case.