| ERROR | [XUST0002] Non-updating expression in a wrong position |
| CAUSE | It is a static error if an non-updating expression other than an empty expression ( ) or a call to the fn: error function is used in one of the following positions: 1. The modify clause of a transform expression. 2. The top-level expression in the body of a function declaration in which the keyword updating is specified. |
| ACTION | None |