- term archives. One problem is that the best versions of arithmetic
- coding are patented (4,286,256 4,295,125 4,463,342 4,467,317
- 4,633,490 4,652,856 4,891,643 4,905,297 4,935,882 4,973,961
- 5,023,611 5,025,258).
+ term archives. See, for example, US Patents 4,286,256 4,295,125
+ 4,463,342 4,467,317 4,633,490 4,652,856 4,891,643 4,905,297
+ 4,935,882 4,973,961 5,023,611 5,025,258, which have all expired.
+ More recent patent-free techniques may also be available.