#2118 ⟨a, b | aba=b, baab=a⟩
Contents
- Properties
- Finite structure
- Cayley table
- Right Cayley graph
- Left Cayley graph
- Rewriting system
- Same cardinality
- Isomorphic instances
- Sum of relation sides is 9
- Finite non-commutative monoid with 13 elements
- Not cancellative, because multiplication by a is not injective:
-
a ⋅ a6 = a and a ⋅ 1 = a, however a6 ≠ 1
Elements in the center commute with all other elements.
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:
- 1 non-trivial idempotent:
- Order of generators:
- a: index 1, period 6
- b: index 1, period 4
- Histogram:
| index 1, period 1 | 1 element | a6 |
| index 1, period 2 | 1 element | a3 |
| index 1, period 3 | 2 elements | a2, a4 |
| index 1, period 4 | 6 elements | b, ba, ba2, ba3, ba4, ... |
| index 1, period 6 | 2 elements | a, a5 |
Idempotents are shown in bold.
|
1 | a | b | a2 | ba | a3 | ba2 | a4 | ba3 | a5 | ba4 | a6 | ba5 |
| 1 | 1 | a | b | a2 | ba | a3 | ba2 | a4 | ba3 | a5 | ba4 | a6 | ba5 |
| a | a | a2 | ba5 | a3 | b | a4 | ba | a5 | ba2 | a6 | ba3 | a | ba4 |
| b | b | ba | a3 | ba2 | a4 | ba3 | a5 | ba4 | a6 | ba5 | a | b | a2 |
| a2 | a2 | a3 | ba4 | a4 | ba5 | a5 | b | a6 | ba | a | ba2 | a2 | ba3 |
| ba | ba | ba2 | a2 | ba3 | a3 | ba4 | a4 | ba5 | a5 | b | a6 | ba | a |
| a3 | a3 | a4 | ba3 | a5 | ba4 | a6 | ba5 | a | b | a2 | ba | a3 | ba2 |
| ba2 | ba2 | ba3 | a | ba4 | a2 | ba5 | a3 | b | a4 | ba | a5 | ba2 | a6 |
| a4 | a4 | a5 | ba2 | a6 | ba3 | a | ba4 | a2 | ba5 | a3 | b | a4 | ba |
| ba3 | ba3 | ba4 | a6 | ba5 | a | b | a2 | ba | a3 | ba2 | a4 | ba3 | a5 |
| a5 | a5 | a6 | ba | a | ba2 | a2 | ba3 | a3 | ba4 | a4 | ba5 | a5 | b |
| ba4 | ba4 | ba5 | a5 | b | a6 | ba | a | ba2 | a2 | ba3 | a3 | ba4 | a4 |
| a6 | a6 | a | b | a2 | ba | a3 | ba2 | a4 | ba3 | a5 | ba4 | a6 | ba5 |
| ba5 | ba5 | b | a4 | ba | a5 | ba2 | a6 | ba3 | a | ba4 | a2 | ba5 | a3 |
Idempotents are shown in bold.
Idempotents are shown in bold.
- Reduction order:
- Left-to-right recursive path with deg(a) = 0; deg(b) = 1
- Certificate: derivations of all rewriting rules from the defining relations.
# ab:aba=b,baab=a a/b - -
aaaaaaa=a
baaaaaa=b
ab=baaaaa
bb=aaa
26 unique, 299 total
| Σ | # | Presentation | Properties | Description | φ |
| 9 | 1328 | ⟨a, b | aaaa=b, abbb=1⟩ | Grp Com 13 | ℤ13 | 189 |
| 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 | 20927 | ⟨a, b | ab=aa, aaaa=bbb⟩ | Noc 13 | | 7 |
| 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.
4 total
| Σ | # | Presentation | Mapping |
| 11 | 19166 | ⟨a, b | aba=b, aaaabb=a⟩ | φ(a) = a, φ(b) = b |
| 11 | 19172 | ⟨a, b | aba=b, aaabba=a⟩ | φ(a) = a, φ(b) = b |
| 11 | 19182 | ⟨a, b | aba=b, aabbaa=a⟩ | φ(a) = a, φ(b) = b |
| 11 | 19190 | ⟨a, b | aba=b, abaaab=a⟩ | φ(a) = a, φ(b) = b |