function h = mintv(A)
[n,n,T] = size(A);
hh = [];
for t=1:T
  h = 1;  
  for i=1:n
    for j=i+1:n
      x = A(:,i,t);
      y = A(:,j,t);
      d = .5*sum(abs(x-y));
      if d<h
        h=d;
      end
    end
  end
  hh(t) = h;
end
return