|  |  7.2.7.1 ring declarations (plural) 
 
Syntax:
ringname= (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 realand 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, orafollowed by a
weight vector given as an intvec_expression in parentheses.
Mfollowed by an intmat_expression in parentheses.
corC. 
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, andWs. 
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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