Properties

This page lists all the properties and their possible values that are currently part of some entry in this database.

Click on a property to get a brief explanation.

Click on the value of a property to see all classes that mention this property with the selected value.

Use the 'Edit text of this page' link to add a new value or property to this list, and then also add it to the relevant database entries.

Classtype	variety, quasivariety, universal class, first-order class, second-order class, higher-order class
Equational theory	decidable (PTIME, NPTIME, PSPACE, EXPTIME,...), undecidable, unspecified (so far)
Quasiequational theory	decidable (PTIME, NPTIME, PSPACE, EXPTIME,...), undecidable, unspecified (so far)
First-order theory	decidable (PTIME, NPTIME, PSPACE, EXPTIME,...), undecidable, unspecified (so far)
Locally finite	yes, no, unspecified (so far)
Residual size	$\kappa$ (cardinality), finite, unbounded
Congruence distributive	yes, no, unspecified (so far)
Congruence modular	yes, no, unspecified (so far)
Congruence n-permutable	yes $n=?$, no, unspecified (so far)
Congruence regular	yes, no, unspecified (so far)
Congruence e-regular	yes, no, unspecified (so far)
Congruence uniform	yes, no, unspecified (so far)
Congruence types	permutational (1), abelian (2), Boolean (3), lattice (4), semilattice (5)
Congruence extension property	yes, no, unspecified (so far)
Definable principal congruences	yes, no, unspecified (so far)
Equationally def. pr. cong.	yes, no, unspecified (so far)
Amalgamation property	yes, no, unspecified (so far)
Strong amalgamation property	yes, no, unspecified (so far)
Epimorphisms are surjective	yes, no, unspecified (so far)