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4.18.2 ring declarations
- Syntax:
ring name = ( coefficients ),
( names_of_ring_variables ),
( ordering );
or
ring name = cring
[ names_of_ring_variables ]
- Default:
(ZZ/32003)[x,y,z]
- Purpose:
- declares a ring and sets it as the actual basering.
The second form sets the ordering to
(dp,C) .
For the second form: cring stands currently for QQ (the rationals), ZZ (the integers)
or (ZZ/m) (the field (m prime and <2147483648) resp. ring of the integers modulo m).
The coefficients for the first form are given by one of the following:
-
a
cring as given above
-
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.
-
an expression_list of the name
integer .
-
an expression_list of the name
integer and following int_expressions.
-
an expression_list of the name
integer and two int_expressions.
For the definition of the 'coefficients', see Rings and orderings.
'names_of_ring_variables' must be a list of names or (multi-)indexed names.
'ordering' is a list of block orderings where each block ordering is either
-
lp , dp , Dp , rp , ls , ds , Ds ,
or rs optionally followed by a size parameter in parentheses.
-
wp , Wp , ws , Ws , 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 .
For the definition of the orderings, see Term orderings,
Monomial orderings.
If one of coefficients, names_of_ring_variables, and ordering
consists of only one entry, the parentheses around this entry may be
omitted.
See also
Examples of ring declarations;
ring;
ringlist.
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