It patents a multiply-linked list, for 2 and 3 links. I don't think most programmers would make the distinction because it's a natural extension to the linked

It patents a multiply-linked list, for 2 and 3 links. I don't think most programmers would make the distinction because it's a natural extension to the linked list. The idea is trivial, and theoretical computer science literature is full of much more complicated graph-based data structures, of the form node + n pointers, each pointer having a different type/color/characteristic. 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".