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BELL SYSTEM TECHNICAL JOURNAL 

 5. Ergodic and Mixed Sources 



As we have indicated above a discrete source for our purposes can be con- 

 sidered to be represented by a Markoff process. Among the possible discrete 

 Markoff processes there is a group with special properties of significance in 



D .2 



Fig. 3 — A graph corresponding to the source in example B. 



Fig. 4 — A graph corresponding to the source in example C. 



Fig. 5 — A graph corresponding to the source in example D. 



communication theory. This special class consists of the ''ergodic" proc- 

 esses and we shall call the corresponding sources ergodic sources. Although 

 a rigorous definition of an ergodic process is somewhat involved, the general 

 idea is simple. In an ergodic process every sequence produced by the proc- 



