Prolog conditional statements

Question

Suppose we are given certain facts and we were supposed to write a certain rule that explores a given condition in those facts, for example, if we are given certain climates and their characteristics:

climate(jun, 20, snow, wind, cold).
climate(jul, 20, hot, dry, calm).
climate(sep, 15, calm, dry, cool).
climate(sep, 16, rain, hot, calm).
climate(sep, 18, warm, rain, calm).
climate(oct, 29, cool, dry, calm).
climate(nov, 1, cold, snow, wind).
climate(nov, 5, hot, snow, wind).
climate(dec, 15, warm, rain, wind).
climate(dec, 21, wind, cold, dry).

If we wanted to find out which climates were hot and dry, would we do something like this:

climatecheck(Month) :-
   climate(Month, _, hot, _, _);
   climate(Month, _, _, hot, _);
   climate(Month, _, _, _, hot),
   climate(Month, _, dry, _, _);
   climate(Month, _, _, dry, _);
   climate(Month, _, _, _, dry).

I tried the method above but it doesnt seem to work.

Instead of giving me:

Month = jul. 

It gives me all the months which have EITHER hot or dry climates.

What could I be doing wrong, despite outlining specific positions of each characteristic with "and" and "or" conditionals? Thank you.

Answer 1

Use parentheses to force the precedence in evaluating your predicate:

climatecheck(Month) :-
   (  climate(Month, _, hot, _, _)
   ;  climate(Month, _, _, hot, _)
   ;  climate(Month, _, _, _, hot)
   ),
   (  climate(Month, _, dry, _, _)
   ;  climate(Month, _, _, dry, _)
   ;  climate(Month, _, _, _, dry)
   ).

Answer 2

climatecheck(Month) :-
   climate(Month, _, X, Y, Z),
   % overkill generalization ahead :)
   maplist([P]>>memberchk(P, [X,Y,Z]), [hot, dry]).

?- climatecheck(Month).
Month = jul ;
false.