Package sagbi/SB.IsInSA

This article is about a function from ApCoCoA-2. If you are looking for the ApCoCoA-1 version of it, see ApCoCoA-1:SB.IsInSubalgebra.

SB.IsInSA

This function tests whether a polynomial is in a given Subalgebra.

Syntax

SB.IsInSA(f: RINGELEM,S: TAGGED("$apcocoa/sagbi.Subalgebra")): BOOL

Description

This function takes a polynomial f and a subalgebra S and tests whether f is an element of S using implicitization.

• @param f A polynomial

• @param S A subalgebra, i.e. of type TAGGED("$apcocoa/sagbi.Subalgebra")

• @return true if f is an element of S and false if not.

Example

Use R ::= QQ[x,y,z];
S := SB.Subalgebra(R,[x^2,y+z]);
f := x^4 +2*x^3*y +x^2*y^2 +x^2 +2*x*y +y^2;
SB.IsInSA(f,S); -- true

See also

Package sagbi/SB.Subalgebra

Package sagbi/SB.IsInSA_SAGBI

Package sagbi/SB.IsInSubalgebra

Package sagbi/SB.IsInSubalgebra_SAGBI

Package sagbi/SB.IsInToricRing