Prolog: why my predicate returns false?

Question

so I wrote a predicate that counts how many times an element occurs in a list of lists.

count([], _, 0).                                  #base case

count([         


        

Answer 1

Ok, it looks like it was backtracking on the part where 'Elem is not the head of sublist', and I was able to fix it by changing it to:

count([[_|Rest]|OtherLists], Elem, Count) :-      #Elem is not the head of sublist
    !,
    count([Rest|OtherLists], Elem, Count).

If anyone can confirm whether this is a correct solution. Thanks