rem: return 1; new = (struct List_element *) xmalloc (sizeof (struct List_element));
add: return false; new = xmalloc (sizeof *new);
context: append_equiv_class (struct Spec_list *list,		    const unsigned char *equiv_class_str, size_t len){  struct List_element *new;  if (len != 1)    return 1;  new = (struct List_element *) xmalloc (sizeof (struct List_element));  new->next = NULL;  new->type = RE_EQUIV_CLASS;  new->u.equiv_code = *equiv_class_str;  assert (list->tail);  list->tail->next = new;  list->tail = new;  return 0;}