SemiBase

Variety V[9618]

The variety generated by [6, 9618]: all semigroups that satisfy every identity of [6, 9618]. 1 semigroup of order six generates it, and 3,687 semigroups of order six lie in it.

Shortest known basis

4 identities irredundant

  1. x²y ≈ xyx
  2. x³y ≈ x²y
  3. xy² ≈ xy³
  4. x²y² ≈ yx²y

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[5553]V[9624]V[2611]V[2612]V[3911]V[9618]
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[9618] in the inclusion graph, with everything above and below it.

Generated by 1 semigroup of order six

Contains 3,687 semigroups of order six

The semigroups of order six that satisfy the basis.

Show all 3,687