#12153 ⟨
a
,
b
|
aaaa
=
aa
,
aabb
=
b
⟩
Up:
Monoid enumeration
Prev:
#12151
⟨
a
,
b
|
aaaa
=
aa
,
aaba
=
b
⟩
Next:
#12156
⟨
a
,
b
|
aaaa
=
aa
,
abba
=
a
⟩
Contents
Properties
Rewriting system
Properties
Sum of relation sides is 11
Infinite non-cancellative non-commutative monoid
Element
ba
has infinite order
Not left cancellative, because left multiplication by
b
is not injective:
b
⋅
b
=
b
and
b
⋅ 1 =
b
, however
b
≠ 1
Not right cancellative, because right multiplication by
b
is not injective:
b
⋅
b
=
b
and 1 ⋅
b
=
b
, however
b
≠ 1
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.
b
2
⇒
b
[4]
2.
a
2
b
⇒
b
[3]
3.
a
4
⇒
a
2
[1]
# ab:aaaa=aa,aabb=b ab - - bb=b aab=b aaaa=aa