#7057 ⟨a, b | ab=aa, aaaa=bb⟩
Contents
- Properties
- Finite structure
- Cayley table
- Right Cayley graph
- Left Cayley graph
- Rewriting system
- Same cardinality
- Isomorphic instances
- Sum of relation sides is 10
- Finite non-commutative monoid with 8 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.
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.
- 4 element center:
- 1 non-trivial idempotent:
- Order of generators:
- a: index 3, period 2
- b: index 2, period 2
- Histogram:
| index 1, period 1 | 1 element | a4 |
| index 1, period 2 | 1 element | a3 |
| index 2, period 1 | 2 elements | a2, ba |
| index 2, period 2 | 2 elements | b, ba2 |
| index 3, period 2 | 1 element | a |
Idempotents are shown in bold.
|
1 | a | b | a2 | ba | a3 | ba2 | a4 |
| 1 | 1 | a | b | a2 | ba | a3 | ba2 | a4 |
| a | a | a2 | a2 | a3 | a3 | a4 | a4 | a3 |
| b | b | ba | a4 | ba2 | a3 | a4 | a4 | a3 |
| a2 | a2 | a3 | a3 | a4 | a4 | a3 | a3 | a4 |
| ba | ba | ba2 | ba2 | a4 | a4 | a3 | a3 | a4 |
| a3 | a3 | a4 | a4 | a3 | a3 | a4 | a4 | a3 |
| ba2 | ba2 | a4 | a4 | a3 | a3 | a4 | a4 | a3 |
| a4 | a4 | a3 | a3 | a4 | a4 | a3 | a3 | a4 |
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:ab=aa,aaaa=bb a/b - -
aaaaa=aaa
baaa=aaaa
ab=aa
bb=aaaa
33 unique, 1204 total
| Σ | # | Presentation | Properties | Description | φ |
| 7 | 188 | ⟨a, b | aab=1, bbbb=1⟩ | Grp Com 8 | ℤ8 | 727 |
| 7 | 330 | ⟨a, b | aa=1, abba=b⟩ | Noc 8 | | 60 |
| 8 | 556 | ⟨a, b | aba=b, aabb=1⟩ | Grp 8 | | 28 |
| 8 | 898 | ⟨a, b | aa=a, bbbb=a⟩ | Noc Com 8 | ℕ(8 = 4) | 48 |
| 8 | 918 | ⟨a, b | aa=b, bbbb=a⟩ | Noc Com 8 | ℕ(8 = 1) | 34 |
| 8 | 919 | ⟨a, b | aa=b, bbbb=b⟩ | Noc Com 8 | ℕ(8 = 2) | 46 |
| 8 | 961 | ⟨a, b | aa=a, aba=bb⟩ | Noc 8 | | 5 |
| 9 | 1605 | ⟨a, b | aaa=bb, abb=b⟩ | Noc Com 8 | ℕ(8 = 3) | 55 |
| 9 | 1606 | ⟨a, b | aaa=bb, bab=a⟩ | Noc Com 8 | | 14 |
| 9 | 1615 | ⟨a, b | aab=aa, baa=b⟩ | Noc 8 | | 14 |
| 9 | 1650 | ⟨a, b | aab=bb, baa=a⟩ | Noc 8 | | 15 |
| 9 | 2206 | ⟨a, b | ab=aa, bbbb=a⟩ | Noc Com 8 | ℕ(8 = 5) | 32 |
| 9 | 2220 | ⟨a, b | bb=aa, aaab=a⟩ | Noc Com 8 | | 22 |
| 9 | 2247 | ⟨a, b | ab=aa, baa=bb⟩ | Noc 8 | | 1 |
| 9 | 2256 | ⟨a, b | ab=aa, bbb=aa⟩ | Noc 8 | | 1 |
| 9 | 2258 | ⟨a, b | ab=aa, bbb=ba⟩ | Noc 8 | | |
| 9 | 2883 | ⟨a, b | aa=a, abbbb=b⟩ | Noc 8 | | 14 |
| 9 | 3107 | ⟨a, b | ab=a, baaa=bb⟩ | Noc 8 | | 9 |
| 9 | 3123 | ⟨a, b | ab=a, bbaa=bb⟩ | Noc 8 | | 10 |
| 10 | 5191 | ⟨a, b | aab=bb, aaaa=b⟩ | Noc Com 8 | ℕ(8 = 6) | 18 |
| 10 | 6664 | ⟨a, b | aab=b, aaaa=ba⟩ | Noc 8 | | 1 |
| 10 | 9380 | ⟨a, b | ab=a, bbbb=baa⟩ | Noc 8 | | 2 |
| 11 | 12606 | ⟨a, b | abbb=aa, bbbb=a⟩ | Noc Com 8 | ℕ(8 = 7) | 14 |
| 11 | 20047 | ⟨a, b | aab=a, bbbb=bbb⟩ | Noc 8 | | |
| 11 | 20051 | ⟨a, b | aab=b, aaaa=abb⟩ | Noc Com 8 | | 1 |
| 11 | 24863 | ⟨a, b | ab=a, aaaaaa=bb⟩ | Noc Com 8 | | |
| 11 | 25112 | ⟨a, b | ab=a, bbbbbb=aa⟩ | Noc Com 8 | | |
| 11 | 25114 | ⟨a, b | ab=a, bbbbbb=ba⟩ | Noc 8 | | |
| 11 | 25411 | ⟨a, b | ab=a, aaaaa=bbb⟩ | Noc Com 8 | | |
| 11 | 25652 | ⟨a, b | ab=a, bbbbb=aaa⟩ | Noc Com 8 | | |
| 11 | 25658 | ⟨a, b | ab=a, bbbbb=bba⟩ | Noc 8 | | |
| 11 | 25897 | ⟨a, b | ab=a, bbbb=aaaa⟩ | Noc Com 8 | | |
| 11 | 25911 | ⟨a, b | ab=a, bbbb=bbba⟩ | Noc 8 | | |
The mapping is from the listed presentation's alphabet to the current rewriting system's alphabet.
7 total
| Σ | # | Presentation | Mapping |
| 10 | 7061 | ⟨a, b | ab=aa, aaab=bb⟩ | φ(a) = a, φ(b) = b |
| 10 | 7065 | ⟨a, b | ab=aa, aaba=bb⟩ | φ(a) = a, φ(b) = b |
| 10 | 7069 | ⟨a, b | ab=aa, aabb=bb⟩ | φ(a) = a, φ(b) = b |
| 10 | 7073 | ⟨a, b | ab=aa, abaa=bb⟩ | φ(a) = a, φ(b) = b |
| 10 | 7077 | ⟨a, b | ab=aa, abab=bb⟩ | φ(a) = a, φ(b) = b |
| 10 | 7081 | ⟨a, b | ab=aa, abba=bb⟩ | φ(a) = a, φ(b) = b |
| 10 | 7085 | ⟨a, b | ab=aa, abbb=bb⟩ | φ(a) = a, φ(b) = b |