Посилання:Classification of L-cross-sections of the finite symmetric semigroup up to isomorphism / E. Bondar // Algebra and Discrete Mathematics. — 2016. — Vol. 21, № 1. — С. 1-17. — Бібліогр.: 5 назв. — англ.
Підтримка:The author acknowledges support from the Ministry of Education and Science of the Russian Federation, project no. 1.1999.2014/K, and the Competitiveness Program of Ural Federal University.
Let Tn be the symmetric semigroup of full transformations on a finite set with n elements. In the paper we give a counting formula for the number of L-cross-sections of Tn and classify all
L-cross-sections of Tn up to isomorphism.