}

	c3 := WithValue(c2, k3, "c3k3")
	check(c3, "c2", "c1k1", "c2k2", "c3k3")

	c4 := WithValue(c3, k1, nil)
	check(c4, "c4", "", "c2k2", "c3k3")

	o0 := otherContext{Background()}
	check(o0, "o0", "", "", "")

	o1 := otherContext{WithValue(Background(), k1, "c1k1")}
	check(o1, "o1", "c1k1", "", "")

	o2 := WithValue(o1, k2, "o2k2")
	check(o2, "o2", "c1k1", "o2k2", "")

00000050  11 ff 01 00 01 00 00 0b  00 04 03 00 01 02 00 17  |................|
00000060  00 00 16 03 03 02 59 0b  00 02 55 00 02 52 00 02  |......Y...U..R..|
00000070  4f 30 82 02 4b 30 82 01  b4 a0 03 02 01 02 02 09  |O0..K0..........|
00000080  00 e8 f0 9d 3f e2 5b ea  a6 30 0d 06 09 2a 86 48  |....?.[..0...*.H|
00000090  86 f7 0d 01 01 0b 05 00  30 1f 31 0b 30 09 06 03  |........0.1.0...|

00000040  5f 95 c5 5c 8d b2 99 5c  fd 30 e5 1b 00 05 00 00  |_..\...\.0......|
00000050  09 ff 01 00 01 00 00 17  00 00 16 03 03 02 59 0b  |..............Y.|
00000060  00 02 55 00 02 52 00 02  4f 30 82 02 4b 30 82 01  |..U..R..O0..K0..|
00000070  b4 a0 03 02 01 02 02 09  00 e8 f0 9d 3f e2 5b ea  |............?.[.|
00000080  a6 30 0d 06 09 2a 86 48  86 f7 0d 01 01 0b 05 00  |.0...*.H........|

00000050  11 ff 01 00 01 00 00 0b  00 04 03 00 01 02 00 17  |................|
00000060  00 00 16 03 03 02 59 0b  00 02 55 00 02 52 00 02  |......Y...U..R..|
00000070  4f 30 82 02 4b 30 82 01  b4 a0 03 02 01 02 02 09  |O0..K0..........|
00000080  00 e8 f0 9d 3f e2 5b ea  a6 30 0d 06 09 2a 86 48  |....?.[..0...*.H|
00000090  86 f7 0d 01 01 0b 05 00  30 1f 31 0b 30 09 06 03  |........0.1.0...|

00000040  06 5e 4b 5a 62 50 c0 d5  89 7f 35 70 00 05 00 00  |.^KZbP....5p....|
00000050  09 ff 01 00 01 00 00 17  00 00 16 03 01 02 59 0b  |..............Y.|
00000060  00 02 55 00 02 52 00 02  4f 30 82 02 4b 30 82 01  |..U..R..O0..K0..|
00000070  b4 a0 03 02 01 02 02 09  00 e8 f0 9d 3f e2 5b ea  |............?.[.|
00000080  a6 30 0d 06 09 2a 86 48  86 f7 0d 01 01 0b 05 00  |.0...*.H........|

		if a.Uses == 0 {
			x.invalidateRecursively(a)
		}
	}

	return
}

func (x *expandState) decomposePair(pos src.XPos, b *Block, a, mem *Value, t0, t1 *types.Type, o0, o1 Op, rc *registerCursor) *Value {
	e := b.NewValue1(pos, o0, t0, a)
	pos = pos.WithNotStmt()
	mem = x.decomposeAsNecessary(pos, b, e, mem, rc.next(t0))
	e = b.NewValue1(pos, o1, t1, a)
	mem = x.decomposeAsNecessary(pos, b, e, mem, rc.next(t1))

00000050  11 ff 01 00 01 00 00 0b  00 04 03 00 01 02 00 17  |................|
00000060  00 00 16 03 03 02 59 0b  00 02 55 00 02 52 00 02  |......Y...U..R..|
00000070  4f 30 82 02 4b 30 82 01  b4 a0 03 02 01 02 02 09  |O0..K0..........|
00000080  00 e8 f0 9d 3f e2 5b ea  a6 30 0d 06 09 2a 86 48  |....?.[..0...*.H|
00000090  86 f7 0d 01 01 0b 05 00  30 1f 31 0b 30 09 06 03  |........0.1.0...|

00000050  11 ff 01 00 01 00 00 0b  00 04 03 00 01 02 00 17  |................|
00000060  00 00 16 03 03 02 59 0b  00 02 55 00 02 52 00 02  |......Y...U..R..|
00000070  4f 30 82 02 4b 30 82 01  b4 a0 03 02 01 02 02 09  |O0..K0..........|
00000080  00 e8 f0 9d 3f e2 5b ea  a6 30 0d 06 09 2a 86 48  |....?.[..0...*.H|
00000090  86 f7 0d 01 01 0b 05 00  30 1f 31 0b 30 09 06 03  |........0.1.0...|

00000050  11 ff 01 00 01 00 00 0b  00 04 03 00 01 02 00 17  |................|
00000060  00 00 16 03 03 02 59 0b  00 02 55 00 02 52 00 02  |......Y...U..R..|
00000070  4f 30 82 02 4b 30 82 01  b4 a0 03 02 01 02 02 09  |O0..K0..........|
00000080  00 e8 f0 9d 3f e2 5b ea  a6 30 0d 06 09 2a 86 48  |....?.[..0...*.H|
00000090  86 f7 0d 01 01 0b 05 00  30 1f 31 0b 30 09 06 03  |........0.1.0...|

00000050  11 ff 01 00 01 00 00 0b  00 04 03 00 01 02 00 17  |................|
00000060  00 00 16 03 02 02 59 0b  00 02 55 00 02 52 00 02  |......Y...U..R..|
00000070  4f 30 82 02 4b 30 82 01  b4 a0 03 02 01 02 02 09  |O0..K0..........|
00000080  00 e8 f0 9d 3f e2 5b ea  a6 30 0d 06 09 2a 86 48  |....?.[..0...*.H|
00000090  86 f7 0d 01 01 0b 05 00  30 1f 31 0b 30 09 06 03  |........0.1.0...|