# Quasi-variety

From Encyclopedia of Mathematics

See Algebraic systems, quasi-variety of.

#### Comments

As noted in (the editorial comments to) Algebraic systems, quasi-variety of, the quasi-identities (cf. Quasi-identity) defining a quasi-variety are usually called Horn sentences. Correspondingly, a quasi-variety is also known as a universal Horn class; it is also called a quasi-primitive class.

#### References

[a1] | P.M. Cohn, "Universal algebra" , Reidel (1981) pp. 235 |

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Quasi-variety.

*Encyclopedia of Mathematics.*URL: http://www.encyclopediaofmath.org/index.php?title=Quasi-variety&oldid=16055