[analog31]

Indeed, a granted patent includes a list of citations, and the presumption is that the office has found that the cited works are not disqualifying prior art. A published patent is assumed to not be self-disqualifying.

I'm not a patent lawyer, but I've been involved in this stuff, often conducting extensive prior art searches. The gold standard for prior art is a single document that teaches everything in the claims of the patent. Often, folks think that they've found prior art if they find one thing in one document and another thing elsewhere. Nope.

Now if you happen to find the pieces of a claim in different prior documents, then you may be able to demonstrate obviousness rather than prior art. For instance it's generally considered obvious to take two patented ideas and combine them together. But obviousness is profoundly harder to prove than straightforward prior art.

Meanwhile, anything that's taught in the body of the patent, can be added to the claims at a later date. Within some limitations of course. A patent can be invalidated in its entirety, and the holder can submit a completely new claim set based on the original body text.

[excessive]

Thank you for your reply, it does actually change how I see the prior art thing played out.

> Often, folks think that they've found prior art if they find one thing in one document and another thing elsewhere. Nope.

Still, I think there must be something profoundly broken if you find the exact math in an old book, and the new patent basically says, "do that math on a computer".

[analog31]

I'd be inclined to agree with you. In fact, as I understand it there are new rules that specifically address so called "with a computer" patents. You weren't supposed to be able to patent a math formula, so instead, people would patent a machine that carries out a math formula.