Translation

A mapping of an algebraic system onto itself that is either the identity mapping or can be expressed as the product of a finite number of principal translations (also called elementary translations). An equivalence relation on an algebraic system is a congruence (in algebra) if and only if it is closed with respect to all translations (or with respect to merely principal translations).

References

[1]	P.M. Cohn, "Universal algebra", Reidel (1981) ISBN 90-277-1213-1 Template:ZBL
[2]	A.I. Mal'tsev, "Algebraic systems", Springer (1973) (Translated from Russian) Template:ZBL