SemiBase

Variety V[7975]

The variety generated by [6, 7975]: all semigroups that satisfy every identity of [6, 7975]. 2 semigroups of order six generate it, and 2,449 semigroups of order six lie in it.

Shortest known basis

4 identities irredundant

  1. x² ≈ x³
  2. xyx ≈ xyx²
  3. xyzx ≈ xzyx
  4. xyxzy ≈ yx²zy

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[13413]V[3339]V[7430]V[7980]V[7975]
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[7975] in the inclusion graph, with everything above and below it.

Generated by 2 semigroups of order six

Contains 2,449 semigroups of order six

The semigroups of order six that satisfy the basis.

Show all 2,449