A categorical genealogy for the congruence distributive property.
A common generalization of permutability and 0-permutability
A finite axiomatization of nondeterministic regular expressions
A Finite Axiomatization of Nondeterministic Regular Expressions
An alternative (tree-based) semantics for a class of regular expressions is proposed that assigns a central rôle to the + operator and thus to nondeterminism and nondeterministic choice. For the new semantics a consistent and complete axiomatization is obtained from the original axiomatization of regular expressions by Salomaa and by Kozen by dropping the idempotence law for + and the distribution law of • over +.
A Galois theory with stable units for simplicial sets.
A new proof of Reiterman's theorem
A normal form for restricted exponential functions
A note on dual discriminator varieties.
A note on finite sets of terms closed under subterms and unification
The paper contains two remarks on finite sets of groupoid terms closed under subterms and the application of unifying pairs.
A note on permutability in varieties
A note on some varieties of point algebras
A note on the finite extensivity property
A note on varieties with distributive subalgebra lattices
A remark on the ideal extension property
A simple basis of ideal terms of Brouwerian semilattices
A survey of algebra of tournaments.
A survey of minimal clones.
A ternary variety generated by lattices
Abstract clones and operads.
Accessible set functors are universal
It is shown that every concretizable category can be fully embedded into the category of accessible set functors and natural transformations.