#1939 ⟨
a
,
b
|
aabaaaba
=
aa
⟩
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Monoids with two generators and one relation
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#1938
⟨
a
,
b
|
aabaaaab
=
bb
⟩
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#1940
⟨
a
,
b
|
aabaaaba
=
ab
⟩
Quick links
Properties
Rewriting system
Properties
Presentation has sum-of-sides 10
Infinite non-cancellative non-commutative monoid
Not left cancellative, because left multiplication by
a
is not injective:
a
⋅
ab
a
3
ba
=
a
2
and
a
⋅
a
=
a
2
, however
ab
a
3
ba
≠
a
Not right cancellative, because right multiplication by
a
is not injective:
a
2
b
a
3
b
⋅
a
=
a
2
and
a
⋅
a
=
a
2
, however
a
2
b
a
3
b
≠
a
Enveloping group: ⟨
a
,
b
|
aabb
⟩
Rewriting system
Format:
Pretty
Plain
Word to reduce:
Tips:
Lowercase letters stand for generators.
Spaces are ignored.
Numbers repeat the previous letter, e.g.
b90
.
Reduction strategy:
Leftmost
Rightmost
Path to normal form:
1
1
Reduction order:
Left-to-right shortlex with
b
<
a
Certificate
: derivations of all rewriting rules from the defining relations.
#
Rule
Proof
1.
a
4
ba
⇒
a
2
b
a
3
[2]
2.
(
a
2
ba
)
2
⇒
a
2
[1]
# ab:aabaaaba=aa ba aaaaba=aabaaa aabaaaba=aa