Package sagbi/SB.IsInSubalgebra
From ApCoCoAWiki
| 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.IsInSubalgebra
Tests whether a polynomial is in a subalgebra.
Syntax
SB.IsInSubalgebra(f:POLY, G:LIST of POLY):BOOL
Description
This function takes a polynomials f and a list of polynomials G and checks whether F is in the algebra generated by the polynomials in G.
@param f A polynomial.
@param G A list of polynomials which generate a subalgebra.
@return true if f is in the subalgebra generated by G, false elsewise.
Example
Use QQ[x[1..2]];
G := [x[1]-x[2], x[1]*x[2]-x[2]^2, x[1]*x[2]^2];
SB.IsInSubalgebra(x[1]*x[2]^4-x[2]^5, G);
-- true
Example
Use QQ[y[1..3]];
G := [y[1]^2-y[3]^2, y[1]*y[2]+y[3]^2, y[2]^2-2*y[3]^2];
SB.IsInSubalgebra(y[3]^4, G);
-- false
See also
Package sagbi/SB.IsInSubalgebra_SAGBI
Package sagbi/SB.IsInToricRing
