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...
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...
James G. Oxley, Charles Semple, Dirk L. Vertigan, ...
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, ...
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...