Article
Keywords:
monounary algebra; 2-homogeneous; 2-set-homogeneous; partially-2-homogeneous; partially-2-set-homogeneous
Summary:
This paper is a continuation of [5], where $k$-homogeneous and $k$-set-homogeneous algebras were defined. The definitions are analogous to those introduced by Fraïssé [2] and Droste, Giraudet, Macpherson, Sauer [1] for relational structures. In [5] we found all 2-homogeneous and all 2-set-homogeneous monounary algebras when the homogenity is considered with respect to subalgebras, to connected subalgebras and with respect to connected partial subalgebras, respectively. The results of [3], where all homogeneous monounary algebras were characterized, were applied in [4] for 1-homogeneity. The aim of the present paper is to describe all monounary algebras which are 2-homogeneous and 2-set-homogeneous with respect to partial subalgebras, respectively; we will say that they are partially-2-homogeneous and partially-2-set-homogeneous.
References:
[2] R. Fraïssé:
Theory of Relations. North-Holland, Amsterdam, 1986.
MR 0832435
[4] D. Jakubíková-Studenovská:
On homogeneous and 1-homogeneous monounary algebras. Contributions to General Algebra 12. Proceedings of the Wien Conference, June 1999, Verlag J. Heyn, 2000, pp. 221–224.
MR 1777661