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

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(Short description update.)
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<command>
 
<command>
 
     <title>BB.ASneighbors</title>
 
     <title>BB.ASneighbors</title>
     <short_description>list of across-the-street neighbors</short_description>
+
     <short_description>Compute a list of across-the-street neighbors.</short_description>
 
<syntax>
 
<syntax>
 
BB.ASneighbors(OO:LIST):LIST
 
BB.ASneighbors(OO:LIST):LIST

Revision as of 16:20, 21 April 2009

BB.ASneighbors

Compute 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 <formula>[i,j,k,l]</formula> such that <formula>x_k * b_i = x_l * b_j</formula>.

Example

Use Q[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