void
f1(record r, ...)
{
    if (~r) {
        for (text s in r) {
            r.delete(s);
            rcall(f1, -2, 0, -1, s);
            r[s] = 0;
        }
    } else {
        ocall(o_, -2, 1, -1, " ", ",");
        o_newline();
    }
}

main(...)
{
    record r;

    ocall(r_put, -2, 1, -1, r, 0);
    f1(r);

    0;
}