// lists as [len, items...], items owned by the list
.u mklist(n) {
	let l = new(n + 1);
	l[0] = 0;
	return u*l;
}
fn push(.m l, .d item) { l[l[0] + 1] = d*item; l[0] = l[0] + 1; return 0; }
fn sum(.m l) { let s = 0, i = 1; while (i <= l[0]) { s += l[i][0]; i++; } return s; }
.u box(v) { let b = new(1); b[0] = v; return u*b; }
fn consume(.d b) { return b[0]; }

fn main() {
	let base = live_objects();
	{
		let l = mklist(8);		// u from mklist arrives m*here
		let i = 0;
		while (i < 5) {
			let b = box(i * 10);	// m in the loop body
			d*b;			// give it down
			push(l, b);
			i++;
		}
		put_n(sum(l)); put_c(' ');
		put_n(live_objects() - base); put_c(' ');	// list + 5 boxes
	}
	put_n(live_objects() - base); put_c(' ');	// freed at the block's end, children too

	// u handed up one block by assignment, and as a block value
	let outer;
	{
		let t = box(7);
		u*t;
		outer = t;
	}
	let v = { let w = box(8); u*w };
	put_n(outer[0] + v[0]); put_c(' ');

	// d given away to a callee
	let g = box(99);
	put_n(consume(d*g)); put_c(' ');

	// containers: child takes its parent's tag
	let p = new(2), c = new(1);
	c[0] = 5;
	p[0] = c;
	p[1] = new(3);
	put_n(p[0][0]); put_c(' ');
	put_n(live_objects() - base); put_c(10);
	return 0;
}