I believe that doublely linked lists are described by Knuth in the Art of Computer Programming volume (something). My recollection is that it may have been in a problem or note. They are definitely used in UNIX for the run queue where rapid traversal was necessary. I recall them from an internals course I took at UNIX expo back in the mid '80's.
Additional pointers are trivially implied so I don't think that this patent should not stand.
Additional pointers are trivially implied so I don't think that this patent should not stand.
What a mess!