UMLR — Limitation on isDimension Partition to be uncontained appears unwarranted

In 15.7.7.6 a constraint state that an isDimension Activity Partition may not be contained in another Activity Partition.

Certain common modeling situations arise that make hierarchical dimensions of more than 2 levels useful.

For example. Let Location be an isDimension ActivityPartition. It could have three lowerlevel partitions: US, EU, Other. Within the US, we could lower-level partitions, NY, Chicago, and Miami and so forth. It seems to me that the US would be also be an isDimension Activity Partition.