# ApCoCoA-1:BB.NDneighbors

From ApCoCoAWiki

## BB.NDneighbors

Compute a list of next-door neighbors.

### Syntax

BB.NDneighbors(OO:LIST):LIST

### Description

Computes the list of next-door neighbors in the border of the order ideal OO. The input is a list OO of terms that specify an order ideal. The output is a list of triples <formula>[i,j,k]</formula> such that <formula>b_i = x_k * b_j</formula>.

#### Example

Use Q[x,y,z]; BB.NDneighbors([1,x]); [[3, 1, 1], [4, 2, 1]] -------------------------------