Prolog. lists predicate to remove an element

Question

Im trying to remove 'b' which is '(b, 10)'. The code i have is:

    remove(C, L1, L2).

    remove(C, [C|N], N).

    remove(C, [C|L1], [C|L2]) :- remove(C, L1, L2).

'C' represents a chest. 'L' represents a location. 'N' represents a number.

Im not sure if im heading in the right direction or if im just missing something little.

Answer 1

you need some correction:

remove(_, [], []).  % drop this if must fail when no element found
remove(C, [(C,_)|N], N) :- !.
remove(C, [A|L1], [A|L2]) :-
    remove(C, L1, L2).

you must pass a matching argument

?- remove(c, [(a,1),(b,2),(c,3),(d,4)], L).
L = [(a,1),(b,2),(d,4)]