SemiBase

Variety V[12958]

The variety generated by [6, 12958]: all semigroups that satisfy every identity of [6, 12958]. 6 semigroups of order six generate it, and 2,930 semigroups of order six lie in it.

Shortest known basis

5 identities irredundant

  1. x² ≈ x³
  2. xyx ≈ xy²x
  3. xyx ≈ xyxyx
  4. x²y²x²y²z ≈ x²y²x²z
  5. xy²z²y² ≈ xz²y²z²y²

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[12952]V[12959]V[7397]V[7434]V[12949]V[12958]
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[12958] in the inclusion graph, with everything above and below it.

Generated by 6 semigroups of order six

Contains 2,930 semigroups of order six

The semigroups of order six that satisfy the basis.

Show all 2,930