4.16.1 ring declarations

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:

1. a non-negative int_expression less or equal 2147483629.
2. an expression_list of an int_expression and one or more names.
3. the name real
4. an expression_list of the name real and an int_expression.
5. an expression_list of the name complex, an optional int_expression and a name.

For the definition of the ’coefficient_field’, see Rings and orderings.

’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

1. lp, dp, Dp, ls, ds, or Ds optionally followed by a size parameter in parentheses.
2. wp, Wp, ws, Ws, or a followed by a weight vector given as an intvec_expression in parentheses.
3. M followed by an intmat_expression in parentheses.
4. c or C.

For the definition of the orderings, see Term orderings, Monomial orderings.

If one of coefficient_field, names_of_ring_variables, and ordering consists of only one entry, the parentheses around this entry may be omitted.