Z:gnu-www-ja-danger-of-software-patents--88e070-These are fairly lightweight c/en

These are fairly lightweight cases: one patent on JPEG, two patents on the LZW algorithm used in GIF. Now you might wonder how come there are two patents on the same algorithm? It's not supposed to happen, but it did. And the reason is that the patent examiners can't possibly take the time to study every pair of things they might need to study and compare, because they're not allowed to take that much time. And because algorithms are just mathematics, there's no way you can narrow down which applications and patents you need to compare.