You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: reduce_pot.m
    path of file: ./repos/bnt/BNT/potentials/@scgpot
    
    the code of the file until where you have to start completion: function [reduced_pot,successful] = reduce_pot(pot,tailnodes)
% Executes the reduce operation defined in
% Stable Local Computation with Conditional Gaussian Distributions
% Steffen L. Lauritzen
% Frank Jensen
% September 1999
% The potential pot is reduced if B contains any zero columns

    
function [reduced_pot,successful] = reduce_pot(pot,tailnodes)
% Executes the reduce operation defined in
% Stable Local Computation with Conditional Gaussian Distributions
% Steffen L. Lauritzen
% Frank Jensen
% September 1999
% The potential pot is reduced if B contains any zero columns
% The test are restricted to the positions in tailnodes.
% Any columns successfully deleted are entered in the array successful
if nargin < 2
    tailnodes = pot.ctaildom;
end