[ Task ] procedure

☞ x ≔ 1.
 {
 	(x = 1) yes: { ✎ write: ‘x’. }, abort.
 	✎ write: ‘y’.
 } procedure.

 {
 	(x = 1) yes: { ✎ write: ‘x’. }, abort.
 	✎ write: ‘y’.
 } × 1.