func: static char *check_nan_suffix(char *s)
  
  {
  
      char *start = s;
  
  
  
      if (*s++ != '(')
  
          return start;
  
  
  
      while ((*s >= 'a' && *s <= 'z') || (*s >= 'A' && *s <= 'Z') ||
  
             (*s >= '0' && *s <= '9') ||  *s == '_')
  
          s++;
  
  
  
      return *s == ')' ? s + 1 : start;
  
  }
  