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Tag Archives: permutations
Permutation patterns, days 35
I never promised to write something every day … Anyway, the conference is now over. The LMS conference wifi was just not up to the demands of a conference big enough to fill the Hardy room, so lots of online … Continue reading
Posted in events
Tagged Fox's theorem, genetics, MarcusTardos theorem, permutations, Peter Sellers, stacks, Stanley Kubrick, StanleyWilf conjecture
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Equivalence relations, 2
I believe, and have said in earlier posts here and here on this blog, that the Equivalence Relation Theorem is the modern pons asinorum, the bridge which you must cross in order to become a mathematician: it is essential to … Continue reading
Posted in doing mathematics
Tagged acyclic orientations, equivalence relations, Moebius inversion, permutations
7 Comments
OuLiPo
OuLiPo, or Ouvroir de Littérature Potentielle (which they translate as “Charity bazaar of potential literature”) were a collection of writers I knew little about until yesterday. I knew a couple of things: Martin Gardner wrote about them, mentioning among other … Continue reading
Posted in mathematics and ...
Tagged Claude Berge, combinations, games, Georges Perec, graphs, groups, literature, orthogonal Latin squares, permutations, Pierre Rosenstiehl
3 Comments
Bijective proofs
A fourth proof Last month I described three proofs of the formula for the number of ways to choose k objects from a set of n, if repetition is allowed and order is not significant; it is the same as … Continue reading
Posted in exposition, open problems
Tagged bijections, Catalan numbers, Catalan objects, Dima FonDerFlaass, permutations, sampling
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Busy times, 4
I meant to finish up the last item with a comment on the relationship between teaching and examining. I have never regarded examining as more than a necessary evil for teachers. So many times, while I was marking the scripts, … Continue reading