process foo {
    value("0123456789") str;

    str->substr("0") sub;
    strcmp(sub, str) a;
    assert(a);

    str->substr("1") sub;
    strcmp(sub, "123456789") a;
    assert(a);

    str->substr("1", "0") sub;
    strcmp(sub, "") a;
    assert(a);

    str->substr("1", "9") sub;
    strcmp(sub, "123456789") a;
    assert(a);

    str->substr("1", "8") sub;
    strcmp(sub, "12345678") a;
    assert(a);

    exit("0");
}