Good work, but when deciphering try to keep in mind there is just so much work that these people will do, which is enough to conceal their intentions of specifics. That being said, when you look for anomalies try looking at the context of when the patterns change and use set theory. For example, two bills backwords could mean a new comm beginning or those two work together. Add, subtract,then try divide, and multiply. Powers and roots are usually to complex. So the bills backwards could end a sequence or be grouped together.