#20927 ⟨a, b | ab=aa, aaaa=bbb⟩
Contents
- Properties
- Finite structure
- Cayley table
- Right Cayley graph
- Left Cayley graph
- Rewriting system
- Same cardinality
- Isomorphic instances
- Sum of relation sides is 11
- Finite non-commutative monoid with 13 elements
- Not cancellative, because multiplication by a is not injective:
-
a ⋅ b = a2 and a ⋅ a = a2, however b ≠ a
Elements in the center commute with all other elements.
The zero element z satisfies zy = yz = z for all y.
An idempotent element x satisfies x2 = x.
The index and period of x is the least m (index) and n (period) such that x(m+n) = xm.
- 3 element center:
- Zero element: b3
- 1 non-trivial idempotent:
- Order of generators:
- a: index 4, period 1
- b: index 3, period 1
- Histogram:
| index 1, period 1 | 1 element | b3 |
| index 2, period 1 | 8 elements | a2, b2, a3, ba2, b2a, ... |
| index 3, period 1 | 2 elements | b, ba |
| index 4, period 1 | 1 element | a |
Idempotents are shown in bold.
|
1 | a | b | a2 | ba | b2 | a3 | ba2 | b2a | b3 | ba3 | b2a2 | b2a3 |
| 1 | 1 | a | b | a2 | ba | b2 | a3 | ba2 | b2a | b3 | ba3 | b2a2 | b2a3 |
| a | a | a2 | a2 | a3 | a3 | a3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| b | b | ba | b2 | ba2 | b2a | b3 | ba3 | b2a2 | b3 | b3 | b2a3 | b3 | b3 |
| a2 | a2 | a3 | a3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| ba | ba | ba2 | ba2 | ba3 | ba3 | ba3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| b2 | b2 | b2a | b3 | b2a2 | b3 | b3 | b2a3 | b3 | b3 | b3 | b3 | b3 | b3 |
| a3 | a3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| ba2 | ba2 | ba3 | ba3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| b2a | b2a | b2a2 | b2a2 | b2a3 | b2a3 | b2a3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| ba3 | ba3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| b2a2 | b2a2 | b2a3 | b2a3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
| b2a3 | b2a3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 | b3 |
Idempotents are shown in bold.
Idempotents are shown in bold.
- Reduction order:
- Left-to-right shortlex with a < b
- Certificate: derivations of all rewriting rules from the defining relations.
# ab:ab=aa,aaaa=bbb ab - -
ab=aa
aaaa=bbb
bbba=bbb
bbbb=bbb
26 unique, 296 total
| Σ | # | Presentation | Properties | Description | φ |
| 9 | 1328 | ⟨a, b | aaaa=b, abbb=1⟩ | Grp Com 13 | ℤ13 | 189 |
| 9 | 2118 | ⟨a, b | aba=b, baab=a⟩ | Noc 13 | | 4 |
| 10 | 4642 | ⟨a, b | aaaa=b, abbb=a⟩ | Noc Com 13 | ℕ(13 = 1) | 10 |
| 10 | 4643 | ⟨a, b | aaaa=b, abbb=b⟩ | Noc Com 13 | ℕ(13 = 4) | 6 |
| 10 | 4683 | ⟨a, b | aaab=b, abba=a⟩ | Noc 13 | | 16 |
| 10 | 5065 | ⟨a, b | aaa=ab, babb=b⟩ | Noc 13 | | 7 |
| 10 | 5334 | ⟨a, b | aaa=ab, bba=bb⟩ | Noc 13 | | |
| 10 | 5336 | ⟨a, b | aaa=ab, bbb=ab⟩ | Noc 13 | | 1 |
| 10 | 5337 | ⟨a, b | aaa=ab, bbb=ba⟩ | Noc 13 | | |
| 10 | 5340 | ⟨a, b | aaa=bb, aab=ba⟩ | Noc 13 | | |
| 10 | 6305 | ⟨a, b | aaa=b, abbbb=b⟩ | Noc Com 13 | ℕ(13 = 3) | 2 |
| 10 | 7143 | ⟨a, b | bb=aa, aaab=ba⟩ | Noc 13 | | 1 |
| 11 | 12240 | ⟨a, b | aaab=aa, bbbb=a⟩ | Noc Com 13 | ℕ(13 = 8) | 1 |
| 11 | 12268 | ⟨a, b | aaab=ab, bbbb=a⟩ | Noc Com 13 | ℕ(13 = 5) | 3 |
| 11 | 12324 | ⟨a, b | aaab=bb, bbbb=a⟩ | Noc Com 13 | ℕ(13 = 2) | 14 |
| 11 | 14647 | ⟨a, b | aaba=b, babbb=a⟩ | Noc Com 13 | | 2 |
| 11 | 15520 | ⟨a, b | aaa=bb, aabbb=b⟩ | Noc Com 13 | | 2 |
| 11 | 16012 | ⟨a, b | aaa=ab, abbb=bb⟩ | Noc 13 | | |
| 11 | 16069 | ⟨a, b | aaa=bb, abbb=ba⟩ | Noc 13 | | 1 |
| 11 | 16205 | ⟨a, b | aab=ab, bbbb=aa⟩ | Noc 13 | | 2 |
| 11 | 16459 | ⟨a, b | aba=bb, abbb=aa⟩ | Noc 13 | | 1 |
| 11 | 16506 | ⟨a, b | aab=ab, bbb=aaa⟩ | Noc 13 | | 1 |
| 11 | 16515 | ⟨a, b | aab=ba, bbb=aaa⟩ | Noc 13 | | |
| 11 | 18958 | ⟨a, b | aab=a, bbbbbb=a⟩ | Noc Com 13 | ℕ(13 = 6) | 4 |
| 11 | 20046 | ⟨a, b | aab=a, bbbb=bba⟩ | Noc 13 | | |
| 11 | 20991 | ⟨a, b | ab=aa, baaa=bbb⟩ | Noc 13 | | 3 |
The mapping is from the listed presentation's alphabet to the current rewriting system's alphabet.
7 total
| Σ | # | Presentation | Mapping |
| 11 | 20935 | ⟨a, b | ab=aa, aaab=bbb⟩ | φ(a) = a, φ(b) = b |
| 11 | 20943 | ⟨a, b | ab=aa, aaba=bbb⟩ | φ(a) = a, φ(b) = b |
| 11 | 20951 | ⟨a, b | ab=aa, aabb=bbb⟩ | φ(a) = a, φ(b) = b |
| 11 | 20959 | ⟨a, b | ab=aa, abaa=bbb⟩ | φ(a) = a, φ(b) = b |
| 11 | 20967 | ⟨a, b | ab=aa, abab=bbb⟩ | φ(a) = a, φ(b) = b |
| 11 | 20975 | ⟨a, b | ab=aa, abba=bbb⟩ | φ(a) = a, φ(b) = b |
| 11 | 20983 | ⟨a, b | ab=aa, abbb=bbb⟩ | φ(a) = a, φ(b) = b |