23 search results - page 1 / 5 » An Infinite Antichain of Permutations |
COMBINATORICS
2000
13 years 4 months ago
2000
We constructively prove that the partially ordered set of finite permutations ordered by deletion of entries contains an infinite antichain. In other words, there exists an infini...
DM
2002
13 years 4 months ago
2002
For each prime p, we construct an infinite antichain of matroids in which each matroid has characteristic set {p}. For p = 2, each of the matroids in our antichain is an excluded m...
ORDER
2002
13 years 4 months ago
2002
We show that: (1) For many regular cardinals (in particular, for all successors of singular strong limit cardinals, and for all successors of singular -limits), for all n {2, 3, ...
COMBINATORICA
2007
13 years 4 months ago
2007
ORDER
2006
13 years 4 months ago
2006
The C-subfunction relations on the set of functions on a finite base set A defined by function classes C are examined. For certain clones C on A, it is determined whether the part...