public static boolean brace_expansion(PsiBuilder b, int l) {
    if (!recursion_guard_(b, l, "brace_expansion")) return false;
    if (!nextTokenIs(b, LEFT_CURLY)) return false;
    boolean r;
    Marker m = enter_section_(b);
    r = consumeToken(b, LEFT_CURLY);
    r = r && brace_expansion_1(b, l + 1);
    r = r && consumeToken(b, RIGHT_CURLY);
    exit_section_(b, m, BRACE_EXPANSION, r);
    return r;
  }
public static boolean brace_expansion(PsiBuilder b, int l)