Prolog help with min,max program

[lekfr97]

I have written this Prolog program:

max(X,Y,X) :- X>=Y.
max(X,Y,Y) :- X<Y.
min(X,Y,X) :- X<Y.
min(X,Y,Y) :- X>=Y.
minlist([X],X).
minlist([X,Y|Rest],Min) :- minlist([Y|Rest],MinRest), min(X,MinRest,Min).
maxlist([X],X).
maxlist([X,Y|Rest],Max) :- maxlist([Y|Rest],MaxRest), max(X,MaxRest,Max).

How can I make it work with one command i.e minmax([1,2,3]) giving the answer 1 and 3? This instead of using two as I do now?

Thank you!

/L

 

[pimi]

Hello.
I can't understand what you want to do correctly, but I guess...

*** program ***

minmax(L, Min, Max) :- minlist(L, Min), maxlist(L, Max).

*** test ***

?- minmax([1, 2, 3], Min, Max).
Min = 1
Max = 3 ;
no

?- minmax([9], Min, Max).
Min = 9
Max = 9 ;
no

?- minmax([7, 8, 6], Min, Max).
Min = 6
Max = 8 ;
no

 

[lekfr97]

Thank you very much. It's very simple now when you know the solution.

Thank you for your help!

/L