nLab subtractive variety

(Stub)

A subtractive variety in the sense of Ursini is a variety $V$ (in the sense of universal algebra) such that the theory of $V$ contains a constant 0 and a subtraction term $s$, i.e. a binary term $s$ satisfying $s(x, x) = 0$ and $s(x, 0) = x$.

References

• Ursini, A.: On subtractive varieties, I. Algebra Universalis 31, 204–222 (1994)