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: eliminateZeroColumns.m
    path of file: ./repos/linear-programming-using-MATLAB/codes/chapter4
    
    the code of the file until where you have to start completion: function [A, c, unbounded] = eliminateZeroColumns(A, c)
% Filename: eliminateZeroColumns.m
% Description: the function is an implementation of the 
% presolve method that eliminates zero columns
% Authors: Ploskas, N., & Samaras, N.
% 
% Syntax: [A, c, unbounded] = eliminateZeroColumns(A, c)
% 
% Input:
% -- A: matrix of coefficients of the constraints 
%    (size m x n)
% -- c: vector of coefficients of the objective function 
%    (size n x 1)
%

    
function [A, c, unbounded] = eliminateZeroColumns(A, c)
% Filename: eliminateZeroColumns.m
% Description: the function is an implementation of the 
% presolve method that eliminates zero columns
% Authors: Ploskas, N., & Samaras, N.
% 
% Syntax: [A, c, unbounded] = eliminateZeroColumns(A, c)
% 
% Input:
% -- A: matrix of coefficients of the constraints 
%    (size m x n)
% -- c: vector of coefficients of the objective function 
%    (size n x 1)
%
% Output:
% -- A: presolved matrix of coefficients of the constraints 
%    (size m x n)
% -- c: presolved vector of coefficients of the objective 
%    function (size n x 1)
% -- unbounded: flag variable showing if the LP is unbounded
%    or not
 
unbounded = 0;
% find the columns that have all their elements equal to zero
delcols = (max(abs(A)) == 0)';
% if any column has all its element equal to zero
if any(delcols == 1)
	% get the indices of all columns that have all their 
	% elements equal to zero
	idelcols = int16(find(delcols));
	% check if the LP problem is infeasible (Case 2)
	if any(c(idelcols) < 0)
		unbounded = 1;
		return;
	end