SemiBase
← [6, 14549][6, 14551] →

[6, 14550] finitely based

self-dualinflation

[6, 14550] is a semigroup with 5 idempotents. It is finitely based: 2 identities define its variety, which 41 other semigroups of order six also generate.

Cayley table

·123456
1113355
2113355
3333355
4444466
5333355
6444466

The product of the row element and the column element, numbered as in Smallsemi. Blue: idempotents on the diagonal.

Structure

Smallsemi
SmallSemigroup(6, 14550)
Idempotents
1, 3, 4, 5, 6
Zero
none
Identity
none
Nilpotent
no
Commutative
no
Regular
no
Group
no
𝒥-classes
3
Rank
2, generated by {2, 6}
Self-dual
yes: anti-isomorphic to itself

Identity basis

Shortest known basis: 2 identities irredundant

  1. xy ≈ xyxy
  2. xyzx ≈ xzyx

Irredundant: none of these identities follows from the others; for each, a semigroup satisfies the others but not it. Obtained from a basis certified in Lean by removing identities that follow from the others, with the prover Vampire; the equivalence rests on Vampire's proofs, not on Lean. Shortest known, not known to be minimal.

Basis certified in Lean: 4 identities

  1. x²y ≈ xy
  2. xy ≈ xy²
  3. xy ≈ xyxy
  4. xyzx ≈ xzyx

Lean proof

Endpoint theorem: SemigroupBasis.Generated.Order6GenericInflationV3.Family07.S6_14550.representative_basis

BasisFor Generated.Order6GenericInflationV3.Family07.S6_14550.table.semigroup
  Generated.Order6GenericInflationV3.Family07.targetBasis
Table
The theorem is about the semigroup with exactly this table.
Method
inflation. This semigroup is an inflation of a smaller one, and the proof adapts the basis of that one.
Size
Checking this class alone compiles 33 Lean files with 20,955 lines: the endpoint theorem and everything it imports, the shared library included. All of it is shared with the proofs of other classes.
Census
SemiBase.Census.S6_14550 checks that the theorem is about the table of this class and concludes Classified; SemiBase.Catalogue.Order6.S6_14550 is the table, with the elements numbered 0 to 5.

Variety

[6, 14550] generates the variety V[7120]; 41 other semigroups of order six generate it too, and 713 semigroups of order six lie in it. [6, 14550] lies in 51 of the 505 varieties of the census, those whose basis it satisfies.

Directly above
Directly below

V[7120] in the inclusion graph, with the varieties above and below it.

Generating the same variety

Nearby tables

Semigroups whose Smallsemi table differs from this one in one or two entries (row, column), as the tables are listed, not up to renumbering.