Homomorphisms of direct powers of algebras
Homomorphisms of direct products of algebras
Homomorphisms of partial unary algebras
Homomorphisms of semigroups of binary relations.
How to make many-sorted algebras one-sorted
Ideals and congruence kernels of algebras
Ideals of binary relational systems
Idempotent pre-generalized hypersubstitutions of type .
Idempotent Subreducts of Semimodules over Commutative Semirings
Independence of Equational Classes
Independent subalgebras of a general algebra
Intersection Graphs of Set Families Closed under Intersection and Satisfying the Descending Chain Condition
Isomorphic algebraic pre-closures and equivalent set-systems
Join-closed and meet-closed subsets in complete lattices
To every subset of a complete lattice we assign subsets , and define join-closed and meet-closed sets in . Some properties of such sets are proved. Join- and meet-closed sets in power-set lattices are characterized. The connections about join-independent (meet-independent) and join-closed (meet-closed) subsets are also presented in this paper.
Korrekturen zur Arbeit: Über die Existenz von freien Algebren. Math. Z. 106, 312 - 320 (1968).
Lattice formulation of general algebraic dependence
Lattices of compatible relations
Lattices of quasiorders on universal algebras
Lattices of tolerances
Linear identities in graph algebras
We find the basis of all linear identities which are true in the variety of entropic graph algebras. We apply it to describe the lattice of all subvarieties of power entropic graph algebras.