It is decidable whether or not a permutation-free morphism is an l code

References

• Berstel , J. and Perrin , D. 1985 . Theory of Codes , New York : Academic Press .
   Google Scholar
• Culik , K. II and Salomaa , A. 1983 . Ambiguity and decision problems concerning number systems . Inform. and Control , 56 : 139 – 153 .
   Google Scholar
• Ehrenfeucht , A. and Rozenberg , G. 1978 . Simplifications of homomorphisms . Inform. and Control , 38 : 298 – 309 .
   Google Scholar
• Honkala , J. 1982 . Unique representation in number systems and L codes . Discrete Appl. Math. , 4 : 229 – 232 .
   Google Scholar
• Honkala , J. 1984 . Bases and ambiguity of number systems . Theoret. Comput. Sci. , 31 : 61 – 71 .
   Google Scholar
• Klöve T. L codes on alphabets with two symbols Report in Informatics Dept. of Math., Univ. of Bergen 1983
   Google Scholar
• Maurer , H. , Salomaa , A. and Wood , D. 1983 . L codes and number systems . Theoret. Comput. Sci. , 22 : 331 – 346 .
   Google Scholar
• Maurer H. Salomaa A. Wood D Paper in preparation
   Google Scholar
• Rozenberg , G. and Salomaa , A. 1980 . The Mathematical Theory of L Systems , New York : Academic Press .
   Google Scholar
• Salomaa , A. 1981 . Jewels of Formal Language Theory , Rockville : Computer Science Press .
   Google Scholar