is_assoc_useless (symbol *s)
{
  return s
      && s->content->assoc != undef_assoc
      && s->content->assoc != precedence_assoc
      && !used_assoc[s->content->number];
}
is_assoc_useless (symbol *s)
{
  return s
      && s->content->assoc != undef_assoc
      && s->content->assoc != precedence_assoc
      && !used_assoc[s->content->number];
}