# ApCoCoA-1:BB.LiftAS

From ApCoCoAWiki

This article is about a function from ApCoCoA-1. |

## BB.LiftAS

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

### Syntax

BB.LiftAS(OO:LIST):LIST

### Description

This command computes the generators of the border basis scheme ideal `I(B_O)` that result from the lifting of across-the-street neighbours.

@param

*OO*A list of terms representing an order ideal with second element of type`POLY`.@return A list of generators of the border basis scheme ideal. 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]] -------------------------------