#1998 ⟨a, b | aaa=a, bbbb=a⟩
Contents
- Properties
- Commutative structure
- Finite structure
- Staircase diagram
- Cayley table
- Right Cayley graph
- Rewriting system
- Same cardinality
- Isomorphic instances
- Sum of relation sides is 9
- Isomorphic to ℕ(12 = 4)
- Finite commutative monoid with 12 elements
- Not cancellative, because multiplication by b4 is not injective:
-
b4 ⋅ b8 = b4 and b4 ⋅ 1 = b4, however b8 ≠ 1
- Gröbner basis: ⟨a, b | b12=b4, a=b4⟩
- Cancellative quotient is isomorphic to ℤ8
- Enveloping group is isomorphic to ℤ8
- Group of units is isomorphic to ℤ1
- 2 Archimedian components:
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.
- 1 non-trivial idempotent:
- Order of generators:
- a: index 1, period 2
- b: index 4, period 8
- Histogram:
| index 1, period 1 | 1 element | b8 |
| index 1, period 2 | 1 element | b4 |
| index 1, period 4 | 2 elements | b6, b10 |
| index 1, period 8 | 4 elements | b5, b7, b9, b11 |
| index 2, period 4 | 1 element | b2 |
| index 2, period 8 | 1 element | b3 |
| index 4, period 8 | 1 element | b |
Idempotents are shown in bold.
|
1 | b | b2 | b3 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 |
| 1 | 1 | b | b2 | b3 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 |
| b | b | b2 | b3 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 | b4 |
| b2 | b2 | b3 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 | b4 | b5 |
| b3 | b3 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 | b4 | b5 | b6 |
| b4 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 | b4 | b5 | b6 | b7 |
| b5 | b5 | b6 | b7 | b8 | b9 | b10 | b11 | b4 | b5 | b6 | b7 | b8 |
| b6 | b6 | b7 | b8 | b9 | b10 | b11 | b4 | b5 | b6 | b7 | b8 | b9 |
| b7 | b7 | b8 | b9 | b10 | b11 | b4 | b5 | b6 | b7 | b8 | b9 | b10 |
| b8 | b8 | b9 | b10 | b11 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 |
| b9 | b9 | b10 | b11 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 | b4 |
| b10 | b10 | b11 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 | b4 | b5 |
| b11 | b11 | b4 | b5 | b6 | b7 | b8 | b9 | b10 | b11 | b4 | b5 | b6 |
Idempotents are shown in bold.
- Reduction order:
- Left-to-right recursive path with deg(b) = 0; deg(a) = 1
- Certificate: derivations of all rewriting rules from the defining relations.
# ab:aaa=a,bbbb=a b/a - -
bbbbbbbbbbbb=bbbb
a=bbbb
37 unique, 653 total
| Σ | # | Presentation | Properties | Description | φ |
| 7 | 124 | ⟨a, b | aab=a, bbb=1⟩ | Noc 12 | | 61 |
| 8 | 458 | ⟨a, b | aaaa=1, abbb=1⟩ | Grp Com 12 | ℤ12 | 325 |
| 8 | 645 | ⟨a, b | ab=aa, bbb=b⟩ | Noc 12 | | 1 |
| 9 | 1646 | ⟨a, b | aab=bb, aba=a⟩ | Noc 12 | | 2 |
| 9 | 1963 | ⟨a, b | aba=b, aaabb=1⟩ | Grp 12 | | 30 |
| 9 | 2018 | ⟨a, b | aaa=b, bbbb=a⟩ | Noc Com 12 | ℕ(12 = 1) | 27 |
| 9 | 2019 | ⟨a, b | aaa=b, bbbb=b⟩ | Noc Com 12 | ℕ(12 = 3) | 23 |
| 9 | 2259 | ⟨a, b | ab=aa, bbb=bb⟩ | Noc 12 | | |
| 10 | 5040 | ⟨a, b | aaa=aa, bbbb=a⟩ | Noc Com 12 | ℕ(12 = 8) | |
| 10 | 5072 | ⟨a, b | aaa=ab, bbbb=a⟩ | Noc Com 12 | ℕ(12 = 5) | 7 |
| 10 | 5092 | ⟨a, b | aaa=bb, bbbb=a⟩ | Noc Com 12 | ℕ(12 = 2) | 43 |
| 10 | 5202 | ⟨a, b | aab=bb, abba=a⟩ | Noc 12 | | 41 |
| 10 | 5330 | ⟨a, b | aaa=ab, bab=bb⟩ | Noc 12 | | 1 |
| 10 | 6597 | ⟨a, b | aaa=b, bbbb=bb⟩ | Noc Com 12 | ℕ(12 = 6) | 4 |
| 10 | 6660 | ⟨a, b | aab=a, bbbb=ba⟩ | Noc 12 | | 1 |
| 10 | 6661 | ⟨a, b | aab=a, bbbb=bb⟩ | Noc 12 | | 1 |
| 10 | 7105 | ⟨a, b | ab=aa, bbaa=bb⟩ | Noc 12 | | 2 |
| 11 | 12897 | ⟨a, b | aab=aaa, baaa=b⟩ | Noc 12 | | 5 |
| 11 | 12910 | ⟨a, b | aab=aaa, bbbb=a⟩ | Noc Com 12 | ℕ(12 = 9) | 2 |
| 11 | 15428 | ⟨a, b | aaa=aa, abbbb=b⟩ | Noc 12 | | |
| 11 | 15996 | ⟨a, b | aaa=ab, aabb=bb⟩ | Noc 12 | | 2 |
| 11 | 16057 | ⟨a, b | aaa=bb, aabb=ab⟩ | Noc 12 | | 4 |
| 11 | 16104 | ⟨a, b | aab=aa, abab=bb⟩ | Noc 12 | | |
| 11 | 16274 | ⟨a, b | aab=bb, aaaa=ab⟩ | Noc 12 | | 1 |
| 11 | 16275 | ⟨a, b | aab=bb, aaaa=ba⟩ | Noc 12 | | |
| 11 | 16448 | ⟨a, b | aba=bb, aabb=aa⟩ | Noc 12 | | 2 |
| 11 | 19773 | ⟨a, b | aba=b, bbbbb=aa⟩ | Noc Com 12 | | |
| 11 | 19917 | ⟨a, b | aaa=b, bbbb=abb⟩ | Noc Com 12 | ℕ(12 = 7) | 2 |
| 11 | 20054 | ⟨a, b | aab=b, aaaa=bba⟩ | Noc 12 | | |
| 11 | 20686 | ⟨a, b | bb=aa, aaaaab=a⟩ | Noc Com 12 | | 15 |
| 11 | 20787 | ⟨a, b | ab=aa, baaaa=bb⟩ | Noc 12 | | 7 |
| 11 | 21086 | ⟨a, b | bb=aa, aaaa=aba⟩ | Noc 12 | | 4 |
| 11 | 21092 | ⟨a, b | bb=aa, aaab=aba⟩ | Noc 12 | | 3 |
| 11 | 21112 | ⟨a, b | bb=aa, abab=aba⟩ | Noc 12 | | |
| 11 | 24147 | ⟨a, b | aa=a, abbbbbb=b⟩ | Noc 12 | | |
| 11 | 24991 | ⟨a, b | ab=a, baaaaa=bb⟩ | Noc 12 | | |
| 11 | 25603 | ⟨a, b | ab=a, bbaaa=bbb⟩ | Noc 12 | | |
The mapping is from the listed presentation's alphabet to the current rewriting system's alphabet.
6 total
| Σ | # | Presentation | Mapping |
| 10 | 6596 | ⟨a, b | aaa=b, bbbb=ab⟩ | φ(a) = b, φ(b) = bbb |
| 11 | 12201 | ⟨a, b | aaaa=bb, aabb=b⟩ | φ(a) = b, φ(b) = bbbbbb |
| 11 | 12203 | ⟨a, b | aaaa=bb, abab=b⟩ | φ(a) = b, φ(b) = bbbbbb |
| 11 | 12205 | ⟨a, b | aaaa=bb, abba=b⟩ | φ(a) = b, φ(b) = bbbbbb |
| 11 | 19842 | ⟨a, b | aaa=a, bbbb=aaa⟩ | φ(a) = bbbb, φ(b) = b |
| 11 | 24859 | ⟨a, b | aa=b, bbbbbb=bb⟩ | φ(a) = b, φ(b) = bb |