Ralph Kimbal thinks because it is not standardized like the Algebra end, it can get convoluted, so a few good men and women who can think calculus wanted to create the OLAP standardizing committee. Microsoft should fund it and call it the Jim Gray OLAP standardizing committee, he helped to standardize the Algebra end so the calculus end committee should be named for him.

http://www.intelligententerprise.com/channels/bi/showArticle.jhtml?articleID=199202330