#2010 ⟨
a
,
b
,
c
|
abc
=
ca
,
bba
=1⟩
Up:
Monoid enumeration
Prev:
#2009
⟨
a
,
b
,
c
|
abc
=
ca
,
bab
=1⟩
Next:
#2011
⟨
a
,
b
,
c
|
abc
=
ca
,
bbb
=1⟩
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
b
is not injective:
b
⋅
bab
=
b
and
b
⋅ 1 =
b
, however
bab
≠ 1
Not right cancellative, because right multiplication by
ba
is not injective:
bab
⋅
ba
=
ba
and 1 ⋅
ba
=
ba
, however
bab
≠ 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 recursive path with deg(
b
) = deg(
c
) = 0,
b
<
c
; deg(
a
) = 1
Certificate
: derivations of all rewriting rules from the defining relations.
#
Rule
Proof
1.
ca
⇒
abc
[1]
2.
b
2
a
⇒ 1
[2]
# abc:abc=ca,bba=1 bc/a - - ca=abc bba=1