static boolean vars(PsiBuilder b, int l) {
    if (!recursion_guard_(b, l, "vars")) return false;
    boolean r;
    r = variable(b, l + 1);
    if (!r) r = composed_var(b, l + 1);
    if (!r) r = command_substitution_command(b, l + 1);
    if (!r) r = old_arithmetic_expansion(b, l + 1);
    return r;
  }
static boolean vars(PsiBuilder b, int l)