#2920 ⟨
a
,
b
,
c
|
aab
=
b
,
aca
=
b
⟩
Up:
Monoid enumeration
Prev:
#2919
⟨
a
,
b
,
c
|
aab
=
b
,
aca
=
a
⟩
Next:
#2921
⟨
a
,
b
,
c
|
aab
=
b
,
aca
=
c
⟩
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
2
ca
=
aca
and
a
⋅
ca
=
aca
, however
a
2
ca
≠
ca
Not right cancellative, because right multiplication by
a
is not injective:
a
3
c
⋅
a
=
aca
and
ac
⋅
a
=
aca
, however
a
3
c
≠
ac
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 recursive path with deg(
a
) = deg(
c
) = 0,
a
<
c
; deg(
b
) = 1
Certificate
: derivations of all rewriting rules from the defining relations.
#
Rule
Proof
1.
a
3
ca
⇒
aca
[4]
2.
b
⇒
aca
[2]
# abc:aab=b,aca=b ac/b - - aaaca=aca b=aca