Definition 3.4
Let
be the unital commutative
algebra over
generated by symbols
Yijk for distinct
indices
,
modulo the anti-cyclicity relations
Yijk=
Y-1jik=
Yjki.
Warning 3.5
Below we will mostly regard
as an
-module, and not as an algebra. Thus we will only use the
product of
as a convenient way of writing certain elements
and linear combinations of elements. The subspaces of
that we
will consider will be subspaces in the linear sense, but not ideals or
subalgebras, and similarly for quotients and maps from or to
.