Yurii V. Zhuchok – Endotypes of Rectangular Relations

Luhansk Taras Scevchenko National University, Starobilsk, Ukraine
The notion of an endotype for a symmetric binary relation was introduced in [1] by means of interrelations between sets of six types of endomorphisms. In [2], all equivalence relations were classified according to their type of an endomorphism. Here we study endotypes of arbitrary rectangular binary relations.


References

[1]
M. Bottcher, U. Knauer, Endomorphism spectra of graphs, Discr. Math. 109 (1992), $45-57$.
[2]
Yu. Zhuchok, Endotypes of equivalence relations, Quasigroups and Related Systems. 22 (2014), $295-300$.