Jira issue originally created by user @guilhermeblanco:
It is not possible to use IdentificationVariable inside an ArithmeticPrimary, although EBNF states that it is possible.
This example would work if this was supported:
FROM fmm:Map m
FROM fmm:PointOfInterest poi
INNER JOIN poi.MapUser mup
INNER JOIN mup.Map m2
WHERE m2 = m
NOTE to the m2 = m
Issue was closed with resolution "Fixed"