comment on the Data Cube vocabulary document

Hello,

I saw the request for comments on the new vocabularies. I have a minor 
comment on the Data Cube document 
<http://www.w3.org/TR/2013/WD-vocab-data-cube-20130312/>: In example 1 
the prefix 'interval' is used, but the namespace is not listed in 
chapter 3 (Namespaces and Document Conventions), nor is it specified 
elsewhere.

Regards,

Frans Knibbe
Geodan <http://geodan.com/>