SemiBase

Variety V[2636]

The variety generated by [6, 2636]: all semigroups that satisfy every identity of [6, 2636]. 3 semigroups of order six generate it, and 4,438 semigroups of order six lie in it.

Shortest known basis

4 identities irredundant

  1. xyx ≈ yx²
  2. x³y ≈ x²y
  3. x²y²x ≈ x²y³
  4. xyzt ≈ yxzt

Irredundant: none of these identities follows from the others; for each, a semigroup satisfies the others but not it. Obtained from a certified basis by removing identities that follow from the others (Vampire). Shortest known, not known to be minimal.

Certified bases

Among the 505 varieties

V[2708]V[5654]V[1041]V[2633]V[2638]V[2636]
Directly above
Directly below

A variety lies above another when it contains it. An inclusion holds when the basis of the smaller variety derives that of the larger one, proved by Vampire; it fails when a semigroup of order six lies in the one and not in the other.

Explore V[2636] in the inclusion graph, with everything above and below it.

Generated by 3 semigroups of order six

Contains 4,438 semigroups of order six

The semigroups of order six that satisfy the basis.

Show all 4,438