function [selected, maxsize] = subset_antirobinson(a)

tic; epsilon=.0000001; [n,n1]=size(a); 
for i = 1:n
  a(i,i) = 0;
end
d = zeros(n,n,n);
for i = 1:n
  for j = 1:n
    if i==j
      continue
    end
    for k = 1:n
      if k==i || k==j
        continue
      end
      if a(i,k) >= a(i,j) && a(i,k) >= a(j,k)
        d(i,j,k) = 1;
      end
    end
  end
end

maxsize = 0; q = zeros(1,n+1); s = zeros(1,n+1);
m = 1; q(m) = 1; s(1) = 1; trig1 = 0; trigend = 0;
while trigend == 0
  if trig1 == 0
    m = m + 1;  trig1 = 1;    % advance pointer
  end
  q(m) = q(m) + 1;
  if s(q(m)) == 1             % redundancy
    continue
  end
  if m == 1 && q(m) > n       % terminate
    trigend = 1;
    continue
  end
  if m > 1 && q(m) > n        % retract
    s(q(m)) = 0; q(m) = 0; m = m - 1; s(q(m)) = 0;
    continue
  end
  test_fail = 0;
  for i = 1:m-2
    for j = i+1:m-1
      if d(q(i),q(j),q(m)) == 0
        test_fail = 1;
        break
      end
    end
    if test_fail == 1
      break
    end
  end
  if test_fail == 0
    if m > maxsize
      maxsize = m; selected = q;
    end
    trig1 = 0; s(q(m))=1;
  end
end
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