Well quasi-orders, unavoidable sets, and derivation systems
نویسندگان
چکیده
منابع مشابه
Well Quasi Orders and the Shuffle Closure of Finite Sets
Given a set I of word, the set Lǫ⊢I of all words obtained by the shuffle of (copies of) words of I is naturally provided with a partial order: for u, v in Lǫ⊢I , u ⊢ ∗ I v if and only if v is the shuffle of u and another word of Lǫ⊢I . In [3], the authors have opened the problem of the characterization of the finite sets I such that ⊢∗I is a well quasi-order on L ǫ ⊢I . In this paper we give an...
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ژورنال
عنوان ژورنال: RAIRO - Theoretical Informatics and Applications
سال: 2006
ISSN: 0988-3754,1290-385X
DOI: 10.1051/ita:2006019