process main {
    value({}) list;
    var("0") i;
    backtrack_point() point;
    num_lesser(i, "100") do_more;
    If (do_more) {
        list->insert(i);
        num_add(i, "1") new_i;
        i->set(new_i);
        point->go();
    };
    val_equal(list.length, "100") a;
    assert(a);
    
    value({}) list;
    var("0") i;
    blocker() blk;
    blk->up();
    blk->use();
    num_lesser(i, "100") do_more;
    If (do_more) {
        list->insert(i);
        num_add(i, "1") new_i;
        i->set(new_i);
        blk->downup();
    };
    val_equal(list.length, "100") a;
    assert(a);
    
    var("true") start;
    var("false") flag;
    backtrack_point() point;
    If (start) {
        blocker() blk;
        blk->up();
        spawn("helper1", {});
        imperative("<none>", {}, "helper3", {}, "1000");
        start->set("false");
        blk->down();
        if("false");
    } Else {
        assert(flag);
    };
    
    exit("0");
}

template helper1 {
    _caller.blk->use();
    imperative("<none>", {}, "helper2", {}, "1000");
    _caller.point->rgo();
}

template helper2 {
    val_equal(_caller._caller.flag, "true") a;
    assert(a);
}

template helper3 {
    val_equal(_caller.flag, "false") a;
    assert(a);
    _caller.flag->set("true");
}