形如xw的双边无限C∞字的组合

The Combination of Bi-infinite C～∞-words as the Form xw

文[1]定理2给出了形如xw的间隙为x(|x|≤4)的双边无限C∞字所确定的无限C∞字w恰有12个.文章在此研究定理2的逆问题,并完全确定了形如w～xw的双边无限C∞字的间隙x的取值,其中w是由定理2确定的12个无限C∞字.

In [1] ,Theorem 2 has established that there are exactly twelve infinite C∞-words w determined by bi-infinite C∞-words as the form xw with the gap ｜x｜≤4. This paper studies the inverse problem in Theorem 2 and gives out the gaps x of bi-infinite C∞-words as the form xw,where w takes the twelve infinite C∞-words determined by Theorem 2 in [2].