#950 ⟨a, b | ab=a, bbbb=a⟩
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- Properties
- Elements
- Staircase diagram
- Cayley table
- Right Cayley graph
- Rewriting system
- Same cardinality
- Isomorphic instances
- Presentation has sum-of-sides 8
- Isomorphic to ℕ(5 = 4)
- Finite commutative monoid with 5 elements
- Not cancellative, because multiplication by a is not injective:
-
a ⋅ a = a and a ⋅ 1 = a, however a ≠ 1
- Commutative Gröbner basis: ⟨a, b | b5=b4, a=b4⟩
- Cancellative quotient is isomorphic to ℤ1
- Enveloping group is isomorphic to ℤ1
- Group of units is isomorphic to ℤ1
- 2 Archimedian components:
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.
- Zero element: b4
- 1 non-trivial idempotent:
- Order of generators:
- a: index 1, period 1
- b: index 4, period 1
- Histogram:
| index 1, period 1 | 1 element | b4 |
| index 2, period 1 | 2 elements | b2, b3 |
| index 4, period 1 | 1 element | b |
Idempotents are shown in bold.
|
1 | b | b2 | b3 | b4 |
| 1 | 1 | b | b2 | b3 | b4 |
| b | b | b2 | b3 | b4 | b4 |
| b2 | b2 | b3 | b4 | b4 | b4 |
| b3 | b3 | b4 | b4 | b4 | b4 |
| b4 | b4 | b4 | b4 | b4 | b4 |
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:ab=a,bbbb=a b/a
bbbbb=bbbb
a=bbbb
11 unique, 1430 total
| Σ | # | Presentation | Description | Related |
| 6 | 44 | ⟨a, b | aa=b, abb=1⟩ | Isomorphic to ℤ5 | 1132 iso |
| 7 | 253 | ⟨a, b | aa=b, abb=a⟩ | Isomorphic to ℕ(5 = 1) | 71 iso |
| 7 | 254 | ⟨a, b | aa=b, abb=b⟩ | Isomorphic to ℕ(5 = 2) | 43 iso |
| 7 | 268 | ⟨a, b | ab=a, baa=b⟩ | Finite non-commutative monoid with 5 elements | 63 iso, 23 anti-iso |
| 8 | 574 | ⟨a, b | aaa=b, aab=b⟩ | Isomorphic to ℕ(5 = 3) | 27 iso |
| 8 | 995 | ⟨a, b | ab=a, aaa=bb⟩ | Finite commutative monoid with 5 elements | 19 iso |
| 8 | 1019 | ⟨a, b | ab=a, bba=bb⟩ | Finite non-commutative monoid with 5 elements | 25 iso |
| 8 | 1020 | ⟨a, b | ab=a, bbb=aa⟩ | Finite commutative monoid with 5 elements | 9 iso |
| 8 | 1022 | ⟨a, b | ab=a, bbb=ba⟩ | Finite non-commutative monoid with 5 elements | 4 iso |
| 10 | 8617 | ⟨a, b | aa=a, abbbba=b⟩ | Finite commutative monoid with 5 elements | 3 iso |
| 11 | 15426 | ⟨a, b | aaa=aa, abbba=b⟩ | Finite commutative monoid with 5 elements | |
The mapping is from the listed presentation's alphabet to the current rewriting system's alphabet.
32 total
| Σ | # | Presentation | Mapping |
| 8 | 985 | ⟨a, b | aa=b, abb=bb⟩ | φ(a) = b, φ(b) = bb |
| 8 | 988 | ⟨a, b | aa=b, bab=bb⟩ | φ(a) = b, φ(b) = bb |
| 9 | 1688 | ⟨a, b | abb=ab, bbb=a⟩ | φ(a) = bbb, φ(b) = b |
| 9 | 1690 | ⟨a, b | abb=ba, bbb=a⟩ | φ(a) = bbb, φ(b) = b |
| 9 | 1696 | ⟨a, b | bab=ab, bbb=a⟩ | φ(a) = bbb, φ(b) = b |
| 9 | 3042 | ⟨a, b | aa=b, aaab=bb⟩ | φ(a) = b, φ(b) = bb |
| 9 | 3046 | ⟨a, b | aa=b, aaba=bb⟩ | φ(a) = b, φ(b) = bb |
| 9 | 3133 | ⟨a, b | ab=a, bbbb=ab⟩ | φ(a) = bbbb, φ(b) = b |
| 9 | 3158 | ⟨a, b | aa=b, abb=aab⟩ | φ(a) = b, φ(b) = bb |
| 9 | 3159 | ⟨a, b | aa=b, abb=aba⟩ | φ(a) = b, φ(b) = bb |
| 9 | 3161 | ⟨a, b | aa=b, baa=abb⟩ | φ(a) = b, φ(b) = bb |
| 9 | 3163 | ⟨a, b | aa=b, bab=aab⟩ | φ(a) = b, φ(b) = bb |
| 9 | 3164 | ⟨a, b | aa=b, bab=aba⟩ | φ(a) = b, φ(b) = bb |
| 10 | 8914 | ⟨a, b | aa=b, aaaaa=bb⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9187 | ⟨a, b | aa=b, aaaa=abb⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9188 | ⟨a, b | aa=b, aaaa=bab⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9191 | ⟨a, b | aa=b, aaab=aab⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9192 | ⟨a, b | aa=b, aaab=aba⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9194 | ⟨a, b | aa=b, aaab=baa⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9199 | ⟨a, b | aa=b, aaba=aab⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9200 | ⟨a, b | aa=b, aaba=aba⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9202 | ⟨a, b | aa=b, aaba=baa⟩ | φ(a) = b, φ(b) = bb |
| 10 | 9379 | ⟨a, b | ab=a, bbbb=abb⟩ | φ(a) = bbbb, φ(b) = b |
| 11 | 14370 | ⟨a, b | aaaa=b, aaaaa=b⟩ | φ(a) = b, φ(b) = bbbb |
| 11 | 19305 | ⟨a, b | aaa=b, aaaaa=ab⟩ | φ(a) = b, φ(b) = bbb |
| 11 | 19849 | ⟨a, b | aaa=b, aaaa=aab⟩ | φ(a) = b, φ(b) = bbb |
| 11 | 19850 | ⟨a, b | aaa=b, aaaa=aba⟩ | φ(a) = b, φ(b) = bbb |
| 11 | 25261 | ⟨a, b | aa=b, aaaaa=aab⟩ | φ(a) = b, φ(b) = bb |
| 11 | 25262 | ⟨a, b | aa=b, aaaaa=aba⟩ | φ(a) = b, φ(b) = bb |
| 11 | 25726 | ⟨a, b | aa=b, aaab=aaaa⟩ | φ(a) = b, φ(b) = bb |
| 11 | 25727 | ⟨a, b | aa=b, aaba=aaaa⟩ | φ(a) = b, φ(b) = bb |
| 11 | 25904 | ⟨a, b | ab=a, bbbb=abbb⟩ | φ(a) = bbbb, φ(b) = b |