#492 ⟨
a
,
b
|
aaaab
=
aab
⟩
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Monoid enumeration
Prev:
#491
⟨
a
,
b
|
aaaab
=
aaa
⟩
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#493
⟨
a
,
b
|
aaaab
=
aba
⟩
Contents
Properties
Rewriting system
Properties
Sum of relation sides is 8
Infinite non-cancellative non-commutative monoid
Element
a
has infinite order
Not left cancellative, because left multiplication by
a
is not injective:
a
⋅
a
3
b
=
a
2
b
and
a
⋅
ab
=
a
2
b
, however
a
3
b
≠
ab
Not right cancellative, because right multiplication by
b
is not injective:
a
4
⋅
b
=
a
2
b
and
a
2
⋅
b
=
a
2
b
, however
a
4
≠
a
2
Rewriting system
Format:
Pretty
Plain
Word:
Enter a word above to compute its normal form. Tips:
Lowercase letters stand for generators.
Spaces are ignored.
Numbers repeat the previous letter, e.g.
b90
.
Strategy:
Leftmost
Rightmost
Result:
1
1
Reduction order:
Left-to-right shortlex with
a
<
b
Certificate
: derivations of all rewriting rules from the defining relations.
#
Rule
Proof
1.
a
4
b
⇒
a
2
b
[1]
# ab:aaaab=aab ab - - aaaab=aab