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7.2.7.1 ring declarations (plural)
- Syntax:
ring name = ( coefficient_field ),
( names_of_ring_variables ),
( ordering );
- Default:
32003,(x,y,z),(dp,C);
- Purpose:
- declares a ring and sets it as the actual basering.
The coefficient_field is given by one of the following:
-
a non-negative int_expression less or equal 2147483647.
-
an expression_list of an int_expression and one or more names.
-
the name
real .
-
an expression_list of the name
real and an int_expression.
-
an expression_list of the name
complex , an optional int_expression
and a name.
'names_of_ring_variables' must be a list of names or indexed names.
'ordering' is a list of block orderings where each block ordering is either
-
lp , dp , Dp ,
optionally followed by a size parameter in parentheses.
-
wp , Wp , or a followed by a
weight vector given as an intvec_expression in parentheses.
-
M followed by an intmat_expression in parentheses.
-
c or C .
As long as all non-commuting variables are global, any ordering may be used. In graded commutative
algebras, one may also use ls, ds, Ds, ws , and Ws .
If one of coefficient_field, names_of_ring_variables, and ordering
consists of only one entry, the parentheses around this entry may be
omitted.
In order to create a non-commutative structure over a commutative ring, use nc_algebra.
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