Difference between revisions of "ApCoCoA-1:BB.ASneighbors"

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   <title>BB.ASneighbors</title>
 
   <title>BB.ASneighbors</title>
   <short_description>Compute a list of across-the-street neighbors.</short_description>
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   <short_description>Computes a list of across-the-street neighbors.</short_description>
 
    
 
    
 
<syntax>
 
<syntax>

Revision as of 12:38, 28 April 2009

BB.ASneighbors

Computes a list of across-the-street neighbors.

Syntax

BB.ASneighbors(OO:LIST):LIST

Description

Computes the list of across-the-street 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 quadruples [i,j,k,l] such that x_k * b_i = x_l * b_j.

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

  • @return A list of across-the-street neighbors of OO.

Example

Use QQ[x,y,z];
BB.ASneighbors([1,x]);
[[1, 2, 2, 3], [3, 4, 2, 3], [3, 5, 1, 3], [4, 5, 1, 2]]
-------------------------------

BB.NDneighbors