I feel like reading comprehension on HN is dropping lately, or at least that some people are willfully choosing to not read entire comments before replying. I specifically said that the patent should not have been granted.
The point is that by being misleading, the anti-patent crowd diminishes their moral standing, and makes it harder for people to take their arguments seriously. This is not simply a "linked list" patent, and anyone with any software development experience who bothers to read past the title should know that.
You are correct in that the patent covers a multiply-linked list. Specifically, one with two or more pointers, where the other pointers allow you to traverse the list in other ways.
One example would be a doubly-linked list, though they would presumably limit that claim by pointing out that the other pointers allow you to traverse the list in any way, not merely backwards.
That said, I don't think you'll find many programmers who think of this as anything but the obvious general type of a linked list or who are confused about what is claimed. I do get your point that pro-patent types (who seem mostly to be lawyers) will seize on any slight inaccuracy, though.
We see obvious generalities. They see them divided up. We're looking for general algorithms that can make our software flexible. They're looking for ideas that are just different enough to patent.
I agree that this is an obvious invention. I think using the unqualified term "linked list" is misleading, though. As I pointed out elsewhere, references typically do not include the "multiply-linked list" when defining the linked list. They'll mention single, doubly, circularly, and possibly sorted linked lists. I don't see any mention of multiply-linked lists (or equivalent) in Intro to Algos or TaoCP. *
* It's possible that TaoCP covers them somewhere, but I don't see them in the early discussion of linked lists.
