The Open University ’ s repository of research publications and other research outputs 2 monotone grid classes are finitely
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The Open University's repository of research publications and other research outputs 2 monotone grid classes are finitely based Journal Article Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online's data policy on reuse of materials please consult the policies page. In this note, we prove that all 2 × 2 monotone grid classes are finitely based, i.e., defined by a finite collection of minimal forbidden permutations. This follows from a slightly more general result about certain 2 × 2 (generalised) grid classes that have two monotone cells in the same row.
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The Open University ’ s repository of research publications and other research outputs 2 monotone grid classes are finitely based
The Open University's repository of research publications and other research outputs 2 monotone grid classes are finitely based Journal Article Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online's data policy on reuse of materials please consult the policies page. In this not...
متن کاملThe Open University ’ s repository of research publications and other research outputs Grid classes and partial well order
We prove necessary and sufficient conditions on a family of (generalised) gridding matrices to determine when the corresponding permutation classes are partially well-ordered. One direction requires an application of Higman’s Theorem and relies on there being only finitely many simple permutations in the only non-monotone cell of each component of the matrix. The other direction is proved by a ...
متن کاملUniversity ’ s repository of research publications and other research outputs Grid classes and partial well order
We prove necessary and sufficient conditions on a family of (generalised) gridding matrices to determine when the corresponding permutation classes are partially well-ordered. One direction requires an application of Higman’s Theorem and relies on there being only finitely many simple permutations in the only non-monotone cell of each component of the matrix. The other direction is proved by a ...
متن کامل’ s repository of research publications and other research outputs Grid classes and partial well order
We prove necessary and sufficient conditions on a family of (generalised) gridding matrices to determine when the corresponding permutation classes are partially well-ordered. One direction requires an application of Higman’s Theorem and relies on there being only finitely many simple permutations in the only non-monotone cell of each component of the matrix. The other direction is proved by a ...
متن کامل’ s repository of research publications and other research outputs The enumeration of permutations avoiding 2143 and 4231
We enumerate the pattern class Av(2143, 4231) and completely describe its permutations. The main tools are simple permutations and monotone grid classes.
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