[ Sau ] daim ntawv theej

☞ a ≔ Sau ← 1 ; 2 ; 3.
☞ b ≔ a daim ntawv theej.
b muab: 999 rau: 1.
✎ sau ntawv: a, tsum.
✎ sau ntawv: b, tsum.
Sau ← 1 ; 2 ; 3
Sau ← 999 ; 2 ; 3