Rephrase the descriptions of the expressions to wrap in expr.access.py

### Description of the modifications

The word'*format* is not exact. May be *syntax*, or simpler, *Scade*.

### Useful links and references

_No response_

Open expr.access.py and locate the expression descriptions that use the word “format.” Confirm whether “syntax” or “Scade” is the intended terminology before editing them. Done means the descriptions use the agreed wording consistently; no test or validation command is mentioned.

Written by the indexing model from the issue text.