[ Cai ] cov-txheej-txheem

var x := 1.
 {
 	(x = 1) muaj-tseeb: { Stdout sau-ntawv: ['x']. }, tawg.
 	Stdout sau-ntawv: ['y'].
 } cov-txheej-txheem.

 {
 	(x = 1) muaj-tseeb: { Stdout sau-ntawv: ['x']. }, tawg.
 	Stdout sau-ntawv: ['y'].
 } × 1.