Patents are essentially by design almost unreadable: the attorneys who put them together are trying to make the patent seem as broad as possible, while the actual operative claims (a tiny fraction of the text) need to be single gargantuan sentences that need to be narrow enough to not be invalidated by prior art.

My guess--and this is only a guess, I can't make enough sense to do anything more--is that the novel part may have something to do with the "credit duration" stuff.