Posts Tagged ‘database’

Refined classification of the degree 4 transformation semigroups

July 16, 2014 Leave a comment

Previously we classified the degree 4 transformation semigroups by size and by the numbers of Green’s classes. This turned out to be insufficient for finding isomorphic semigroups, so we needed a finer classification. The new property is the number of idempotents, for instance, I016 in the filename means the semigroups in the file all contain 16 idempotents. Furthermore, letter b indicates bands, letter c commutative semigroups, and r stands for regular semigroups.

The size of the archive is around the same, but there are more files in it. 287401 to be precise.