5 papers · 1 filter
Orthogonal adjointness in posets with
Michal Botur, Ivan Chajda, Helmut Länger
Motivated by the concept of polarity introduced by G. Birkhoff for a binary relation on a set, we introduce a concept of orthogonality in a poset with . A pair of operators ,…
Residuated mappings and homomorphisms in posets
Ivan Chajda, Helmut Länger
The concept of weakly regular residuated mappings was investigated for lattices recently by S. Radeleczki and L. Veres. We modify this concept for posets. We define so-called opera…
Congruences on posets, relatively pseudocomplemented and Boolean posets
Ivan Chajda, Helmut Länger
The aim of the present paper is to extend the concept of a congruence from lattices to posets. We use an approach different from that used by the first author and V. Snášel. By usi…
Induced orthogonality in semilattices with 0 and in pseudocomplemented lattices and posets
Ivan Chajda, Miroslav Kolařík, Helmut Länger
On an arbitrary meet-semilattice S with 0 we define an orthogonality relation and investigate the lattice Cl(S) of all subsets of S closed under this orthogonality. We show that if…
A characterization of permutability of 2-uniform tolerances on posets
Ivan Chajda, Helmut Länger
Tolerance relations were investigated by several authors in various algebraic structures, see e.g. the monograph by I. Chajda. Recently G. Czédli studied so-called 2-uniform tolera…