function [Ainf,Binf] = lipab(m,n)
d = 1;
mn = m^n;
L = mn;
Ainf = zeros(L,mn);
Binf = zeros(L,1);
MN = repmat([m],[1 n]);
rind = 0;
for ind1 = 1:mn
  for ind2 = ind1+1:mn
    x = ind2coord(ind1,MN);
    y = ind2coord(ind2,MN);
    if length(find(x~=y))==1  % Hamming dist == 1
      for s = [-1,1]
        rind = rind+1;
        Ainf(rind,ind1) =  s;
        Ainf(rind,ind2) = -s;
        Binf(rind,1) = d;
      end
    end
  end
end
return