Independence of Equational Classes
Independent axiomatization of varieties of lattice ordered groups
Injectives in equational classes of idempotent semigroups.
Interpreting set theory in the endomorphism semi-group of a free algebra or in a category
Introduction à la théorie axiomatique des structures.
Invariants of the rational equivalence.
Isotopy invariant quasigroup identities
According to S. Krstić, there are only four quadratic varieties which are closed under isotopy. We give a simple procedure generating quadratic identities and deciding which of the four varieties they define. There are about 37000 such identities with up to five variables.
Mal'cev type conditions for two varieties
Minimal algebras and category equivalences
Minimal generics of some regular varieties
Modulare Polynomverbände über endlichen distributiven Verbänden.
Multiple radical theories
Nd-solid varieties
A non-deterministic hypersubstitution maps any operation symbol of a tree language of type τ to a set of trees of the same type, i.e. to a tree language. Non-deterministic hypersubstitutions can be extended to mappings which map tree languages to tree languages preserving the arities. We define the application of a non-deterministic hypersubstitution to an algebra of type τ and obtain a class of derived algebras. Non-deterministic hypersubstitutions can also be applied to equations of type τ. Formally,...
Nonfinitely based pseudovarieties and inherently nonfinitely based varieties.
Not every equational class of infinitary algebras contains a simple algebra
On a Non-Abelian Variety of Groups which are Symmetric Algebras.
On a representation of semigroups by products of algebras and relations
On algebras of relations
On atoms in lattices of primitive classes