Generation error on OCL constraint when restrict double to int

In BBR chcda, template cdach_entry_InabilityToWorkObservation, there is the PQ datatype that has its @value restricted from double to int.

This generate a OCL constraint such as
context cdach_entry_InabilityToWorkObservation
inv: self.value->select(oclIsKindOf(PQ)).oclAsType(PQ)->forAll(value.oclIsUndefined() or CommonOperationsStatic::matches(value.toString(), '\d*'))

However value.toString() cannot be applied on a double, this makes the compilation of generated validator failing.