Génère l'événement DROP_LISTEN.

declare
        p_li_origin             alias for $1;
        p_li_provider   alias for $2;
        p_li_receiver   alias for $3;
begin
        perform dropListen_int(p_li_origin, 
                        p_li_provider, p_li_receiver);
        
        return  createEvent ('_schemadoc', 'DROP_LISTEN',
                        p_li_origin::text, p_li_provider::text, p_li_receiver::text);
end;