Package sagbi/SB.IsInSubalgebra

From ApCoCoAWiki
< Package sagbi
Revision as of 10:43, 27 September 2020 by Andraschko (talk | contribs) (Created page with "{| cellspacing="8" cellpadding="0" style="background-color:#eeeeff; width:100%; font-size:95%; border-bottom: 2px solid blue; border-top: 2px solid blue; position:top; clear:b...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
This article is about a function in ApCoCoA-2.0. If you are looking for the ApCoCoA-1.0 version of it, see ApCoCoA:SB.Sagbi.


Tests whether a polynomial is in a subalgebra.


SB.IsInSubalgebra(f:POLY, G:LIST of POLY):BOOL


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. For the function

  • @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.


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);


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);