ApCoCoA-1:BB.LiftAS

From ApCoCoAWiki
Revision as of 12:48, 28 April 2009 by Stadler (talk | contribs)

BB.LiftAS

Computes the border basis scheme ideal generators obtained from lifting of AS neighbours.

Syntax

BB.LiftAS(OO:LIST):LIST

Description

Computes the generators of the border basis scheme ideal I(B_O) that result from the lifting of across-the-street neighbours. The input is a list of terms OO (2nd element of type POLY). The output is a list of poly in the ring BBS=K[c_{ij}].

  • @param OO A list of terms representing an order ideal.

  • @return A list of generators of the border basis scheme ideal I(B_O) that results from the lifting of across-the-street neighbours in the border of OO. The polynomials will belong to the ring BBS=K[c_{ij}].

Example

Use QQ[x,y], DegRevLex;
BB.LiftAS([Poly(1), x, y, xy]);

[BBS :: c[1,2]c[2,3] - c[1,1]c[3,4] + c[1,4]c[4,3] - c[1,3]c[4,4],
 BBS :: c[2,2]c[2,3] - c[2,1]c[3,4] + c[2,4]c[4,3] - c[2,3]c[4,4] + c[1,3],
 BBS :: c[2,3]c[3,2] - c[3,1]c[3,4] + c[3,4]c[4,3] - c[3,3]c[4,4] - c[1,4],
 BBS :: c[3,4]c[4,1] - c[2,3]c[4,2] + c[2,4] - c[3,3]]
-------------------------------

BB.LiftASViaServer

BB.LiftHomAS

BB.LiftND

BB.LiftNDViaServer

BB.LiftHomND