Re: How can i get the count of each number in a file ?

Suppose you have a list of ground terms and want to get a list of
(Term, Count) pairs.  The Unix shell equivalent would be
	sort <input | uniq -c 

So

	member_counts(List, Member_Counts) :-
	    attach_weights(List, List_With_Weights),
	    keysort(List_With_Weights, Sorted_List_With_Weights),
	    add_weights(Sorted_List_With_Weights, Member_Counts).

	attach_weights([], []).
	attach_weights([X|Xs], [X-1|Pairs]) :-
	    attach_weights(Xs, Pairs).

	add_weights([], []).
	add_weights([X-W|Pairs], Member_Counts) :-
	    add_corresponding_weights(Pairs, X, W, Member_Counts).

	add_corresponding_weights([X-W1|Pairs], X, W0, Member_Counts) :- !,
	    W2 is W0 + W1,
	    add_corresponding_weights(Pairs, X, W2, Member_Counts).
	add_corresponding_weights(Pairs, X, W, [X-W|Member_Counts]) :-
	    add_corresponding_weights(Pairs, Member_Counts).

I'd stick with Member - Count rather than (Member, Count) if I were you.