Permutations of context-free and indexed languages
نویسندگان
چکیده
We consider the cyclic closure of a language, and its gener-alisation to the operators C k introduced by Brandstädt. We prove that the cyclic closure of an indexed language is indexed, and that if L is a context-free language then C k (L) is indexed.
منابع مشابه
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عنوان ژورنال:
- CoRR
دوره abs/1412.5512 شماره
صفحات -
تاریخ انتشار 2014