Ⅰ. INTROOUCTIONLet X be a nonempty finite set called an alphabet, and X~* the free monoid generated by X and X^+=X~*—{1}, where 1 is the identity of X~* called the empty word over X. Elements and subsets of X~* are ...Ⅰ. INTROOUCTIONLet X be a nonempty finite set called an alphabet, and X~* the free monoid generated by X and X^+=X~*—{1}, where 1 is the identity of X~* called the empty word over X. Elements and subsets of X~* are called words and languages over X respectively. The length of a word x which is the number of the letters occurring in x will be denoted by lg(x).展开更多
By means of further investigation of solid codes,the problem“Is every fd-domain uni- formly dense”proposed by Yuqi Guo,C.M.Reis and G.Thierrin in 1988 is solved in this paper.
基金This research has been supported by the National Research Council of Canada under Grants A7877 and A7350, respectively. The Project is supported by the National Natural Science Foundation of China.
文摘Ⅰ. INTROOUCTIONLet X be a nonempty finite set called an alphabet, and X~* the free monoid generated by X and X^+=X~*—{1}, where 1 is the identity of X~* called the empty word over X. Elements and subsets of X~* are called words and languages over X respectively. The length of a word x which is the number of the letters occurring in x will be denoted by lg(x).
基金This work was partially supported by the National Natural Science Foundation of China(Grant No.10471112)the Educational Committee Foundation(ECF)of Yunnan Province of China(Grant No.04Y583A)
文摘By means of further investigation of solid codes,the problem“Is every fd-domain uni- formly dense”proposed by Yuqi Guo,C.M.Reis and G.Thierrin in 1988 is solved in this paper.
