SYNOPSIS
        varargs int id(string str, int lvl);

DESCRIPTION
        Let the object identify itself. If str matches an id of the
        current object then return a none zero value.

        This lfun is applied for the efun present().

EXAMPLE
        int id(string str) {
           return "sword" == str || "sword of fire" == str;
        }

SEE ALSO
        present(E)
        id(L)