   return consp(first(args)) ? tee : nil;
 }
 
-object *fn_numberp (object *args, object *env) {
-  (void) env;
-  object *arg = first(args);
-  return numberp(arg) ? tee : nil;
-}
-
 object *fn_symbolp (object *args, object *env) {
   (void) env;
   object *arg = first(args);

  return tee;
}

object *fn_plusp (object *args, object *env) {
  (void) env;
  int arg = integer(first(args));

  
  if (form == NULL) return nil;

  if (integerp(form) || characterp(form) || stringp(form)) return form;

  if (symbolp(form)) {
    symbol_t name = form->name;
