Variety V[8921]
The variety generated by [6, 8921]: all semigroups that satisfy every identity of [6, 8921]. 7 semigroups of order six generate it, and 3,320 semigroups of order six lie in it.
Shortest known basis
2 identities irredundant
- x³y ≈ xy
- xyzxz ≈ xyz²x
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
- 8 identities, certified in Lean for 7 semigroups
Among the 505 varieties
- 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[8921] in the inclusion graph, with everything above and below it.
Generated by 7 semigroups of order six
Contains 3,320 semigroups of order six
The semigroups of order six that satisfy the basis.