Applied dimensionality

Break-back (write-back, back-solve, anyway you like) is crucial for performing what-if analysis. Being a techie lately and, moreover, writing a PHD on OLAP subject I wanted to find out how that technique is realized in Cognos EP, MS AS and others.
Well, they don't write that in documentation for sure. But there's a very good thing about US -- a lot of information is open. For example, most of patents.
So here we go (with all the respect to honored inventors) :
write-back in MS AS
break-back in Analyst and Contributor
Overall Cognos Enterprise Planning ideas
Mapping Accounting Info into MDDB by Applix
Mapping Accounting Info into MDDB by Hyperion
All Cognos Patents

Two excellent patent searching services:
www.freepatentsonline.com
a fresh&new www.google.com/patents (yet no pdf export for now, they'll do it very soon, I suppose)