[ Daim-ntawv-qhia ] - [ Lub-Hom-Phiaj ]

var x := Daim-ntawv-qhia tshiab.
x aaa: ['bbb'], ccc: ['ddd'].
x - ['ccc'].
Stdout sau-ntawv: x, tsum.
(Daim-ntawv-qhia tshiab) muab:['bbb'] rau:['aaa']