On Better-Quasi-Ordering Countable Series-Parallel Orders
نویسندگان
چکیده
منابع مشابه
On Better-Quasi-Ordering Countable Series-Parallel Orders
We prove that any infinite sequence of countable series-parallel orders contains an increasing (with respect to embedding) infinite subsequence. This result generalizes Laver’s and Corominas’ theorems concerning better-quasi-order of the classes of countable chains and trees. Let C be a class of structures and ≤ an order on C. This class is well-quasi-ordered with respect to ≤ if for any infini...
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ژورنال
عنوان ژورنال: Transactions of the American Mathematical Society
سال: 1999
ISSN: 0002-9947,1088-6850
DOI: 10.1090/s0002-9947-99-02400-9