Axioms and uniqueness theorem for Tsallis entropy
  The Shannon-Khinchin axioms for the ordinary information entropy are generalized in a natural way to the nonextensive systems based on the concept of nonextensive conditional entropy, and a complete proof of the uniqueness theorem for the Tsallis entropy is presented. 
Sumiyoshi Abe (College of Science and Technology, Nihon University,   Funabashi, Chiba, Japan)