For simple graphs, we investigate and seek to characterize the properties first-order definable by the induced subgraph relation. Let $${\mathcal{P}\mathcal{G}}$$PG denote the set of finite… Expand

It is shown that if T c denotes the structure with all unary singleton relations in addition to the edge relation of the tournament, then it will follow that the constraint satisfaction problem with template T c satisfies the algebraic dichotomy conjecture.Expand

A quasi-Mal’cev condition for quasivarieties is established which in the case of locally finite quasivarieties forbids strongly abelian congruences and for varieties is equivalent to possessing a… Expand

We establish a characterization of supernilpotent Mal’cev algebras which generalizes the affine structure of abelian Mal’cev algebras and the recent characterization of 2-supernilpotent Mal’cev… Expand

We investigate the complexity of the partial order relation of Young's lattice. The definable relations are characterized by establishing the maximal definability property modulo the single… Expand