Software Patents are Self-Defeating
blog.datamules.com
blog.datamules.com
How does that follow?
It certainly isn't true with physical device patents, like automatic transmission mechanisms, so why would software be any different?
> I doubt whether our software could be patented anyway, but if you can patent a [linked list](http://www.google.com/patents/US7028023), perhaps it could be after all
If this guy knows so little about patents that he thinks the title of that patent defines what it protects, and apparently has not even looked at the claims, then why should I listen to his opinion about them?
Claim 1 - Linked list with two traversal orders Claim 2 - Linked list with three traversal orders Claim 3 - Method of traversing the lists in claim 1 and 2 Claim 4 - A device (computer) to traverse the lists in claim 1 and 2
See what I mean?
> The present invention overcomes the disadvantages and limitations of the prior art by providing a system and method for traversing a list using auxiliary pointers that indicate the next item in a sequence.
The "invention" here is called a sentinel, and have been used in conjunction with linked lists since time immemorial. For "prior art" I would refer you to CLRS.
Go ahead and downvote me. Please.
Also,
> Go ahead and downvote me. Please.
Yawn. And you can't downvote someone's reply to your own post, btw.
That's exactly what I'm saying. For all the patent's talk of primary, tertiary, and secondary pointers, the "invention" here is a standard linked list with sentinels. If I hired a patent attorney to write patents against the programs I wrote for my freshman-year data structures course, the results would be much the same.
And I don't have any agenda here, other than to promote intelligent discussion about patents in a place where that happens too little.
... Which is pretty strange, actually, since the patent itself references prior art involving doubly-linked lists. Maybe that's why they had a separate claim for a list with three "next" pointers in each node. I have no idea why claims 1, 3 add 4 weren't thrown out by the examiner given that everything they describe is done by every doubly-linked list implementation anywhere ever. (Claim 2 looks obviously not novel to me, but it's not quite such a slam-dunk as the others.)
So, anyway. The patent is preposterous. It isn't a patent on The Linked List. It doesn't involve sentinels. It doesn't cover any singly-linked list. It does cover any doubly-linked list (which is one reason why it's preposterous). The author of the OP is right about the patent's preposterousness but wrong to describe it as "patent[ing] a linked list". monochromatic is right that the patent isn't a patent on the linked list, but arguably wrong to think this proves the original author is a twit (perhaps s/he knows perfectly well what the patent purports to cover, but preferred terseness to precision). rtperson is wrong to say that the patent is about "a standard linked list with sentinels", wrong to be obnoxious about it, but probably right that there's prior art in CLRS at least for claims 1,3,4.
There is no functional difference between the patented data structure and 2 or 3 separate linked lists, other than storage space and ease of altering node data that's shared between lists. No mention is made of traversal using varying types of link/edge depending on internal state; the patent describes traversal using [one set of] the auxiliary pointers exclusively.
Although you may have a point that this patent does not cover the canonical 1-pointer linked list, LSI nevertheless patented a very small subset of common graph structures, which were well known (not novel), trivial, and which I think most programmers still call "linked lists".
How I wish that were the case. Unfortunately, there are hundreds of patent trolls out there that would love to use their patents to extract value from your company. When the trolls come knocking (and they will), having a patent of your own may literally be the only defense.
Everyone who wants to understand just how incredibly corrupt the US patent system is needs to do themselves a favor and listen to the "When Patents Attack" episode of NPR's This American Life. Then you'll understand why neatly-reasoned arguments are, in this instance, entirely besides the point.
Patents are also not supposed to overlap each other. However -- and again this was made startlingly clear by NPR -- they do, and by the tens of thousands.
You're making the mistake of believing yourself to be in a world where reasonableness prevails.
It would be a weak form of defensive patent aggregation (http://en.wikipedia.org/wiki/Patent_troll#Defenses), but it would still be better than nothing.
My larger point is that, by vocally opting out of the patent game, the author of the original article has practically painted a bullseye on himself. Averring yourself to be above the fray seems to me to be a sure-fire way to be victimized yourself.
Now, your own patent could in some circumstances be used as prior art against the patent troll... but if that's all you're using it for, why not just publish everything you're doing? Publications are prior art just as much as patents are.
What, exactly is this "basis"?
Note that a given thing can be covered by multiple patents, owned by different people.
Yes, patents can be prior art against other patents, but you don't need to own a patent to use it as prior art.