SP::Sp2TableVar --
variable set for the SP package
Call(s)
SP::Sp2TableVar(expr)
Parametersexpr | - | any expression |
Introduction
The SP::Sp2TableVar function returns a table whose entries describe the
set of all Schubert polynomials and variables that appear in a given
expression expr.
The indices of the table are taken into the global variable SP::SPBases.
For all bases of type _index (SP::SPBasesIndexed), the entry
consists of the set of all permutations that index the corresponding Schubert
polynomials in expr.
For all bases of type DOM_IDENT (SP::SPBasesString), the entry
consists of the set of all integers that index the corresponding variable in
expr.
An entry equal to an empty set means that the element does not appear in
expr.
One can add a second argument to select some elements among those in
SP::SPBases.
If the second argument is a set of names, then the restriction to this set of
indices of the table is returned.
In case the second argument is a single name, then the corresponding entry in
the table is returned instead of the table.
Example 1>> muEC::SP::Sp2TableVar(x1^3*x4*y4 + q*y6*X[4,1,3,2]*X[2,3,1]);
table(
Pe = {},
YY = {},
Y = {},
XX = {},
X = {[2, 3, 1], [4, 1, 3, 2]},
y = {4, 6},
x = {1, 4}
)
>> muEC::SP::Sp2TableVar(x1^3*x4*y4 + q*y6*X[4,1,3,2]*X[2,3,1], {X, x});
table(
X = {[2, 3, 1], [4, 1, 3, 2]},
x = {1, 4}
)
>> muEC::SP::Sp2TableVar(x1^3*x4*y4 + q*y6*X[4,1,3,2]*X[2,3,1], y);
{4, 6}
Related FunctionsMuPAD Combinat, an open source algebraic combinatorics package