Facteurs et plans. I : Structure de finesse
f-closure algebras
Finite atomistic lattices that can be represented as lattices of quasivarieties
We prove that a finite atomistic lattice can be represented as a lattice of quasivarieties if and only if it is isomorphic to the lattice of all subsemilattices of a finite semilattice. This settles a conjecture that appeared in the context of [11].
Finite hull systems and their implication bases. (Endliche Hüllensysteme und ihre Implikationenbasen.)
Function classes and relational constraints stable under compositions with clones
The general Galois theory for functions and relational constraints over arbitrary sets described in the authors' previous paper is refined by imposing algebraic conditions on relations.
Function spaces and fixed point properties: a Galois connection.
Functional Completeness and Automorphisms.I.
Fuzzy concepts defined via residuated maps