Academic Editor: Abdel-Maksoud A. Soliman
    
        Copyright © 2012 Shou-feng Wang. This is an open access article distributed under the   Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
        
     
Abstract
Regular fuzzy languages are characterized by some algebraic approaches. In particular, an extended version of Myhill-Nerode theorem for fuzzy languages is obtained.