极大强码  

Strong Maximal Codes

作　　者：邱伟德[1] 

机构地区：[1]计算机工程与科学学院

出　　处：《上海大学学报（自然科学版）》1998年第6期600-604,共5页Journal of Shanghai University:Natural Science Edition

摘　　要：本文给出极大强码的二个等价定义，设Ａ是字母表，（１）设Ｍ是Ａ＊的子么半群，Ｍ≠，Ｍ≠｛１｝，ａｌｐｈ（Ｍ）＝Ａ，Ｍ满足性质：若ｕｖ∈Ｍ，ｕｗｖ∈Ｍ，则ｗ∈Ｍ的充要条件是Ｍ由一个极大强码生成．（２）设φ：Ａ＊→Ｇ是满同态，Ｇ是群，Ｈ是Ｇ的正规子群，Ｍ＝φ－１（Ｈ），则Ｍ的基是极大强码．We give two equivalent definitions of strong maximal codes. Let A be a alphabet. (1) Let M be a submonoid of A * and M≠, M≠{1}, alph (M)=A. Then M satisfies the condition: uv∈M, uwv∈Mw∈M if and only if M is gene rated by a strong maximal code. (2) Let G be a group. H be a normal subgroup of G and φ:A *→G be a surjective morphism. Then the M=φ -1 (H) is generated by a strong maximal code. We research properties of strong codes +, w(u) and syntactic monoid syn( ∪{1} ) also.

关 键 词：强码 上下文无关语言 极大强码 么半群 

分 类 号：O152.7[理学—数学]