function [h,i1,i2,t0] = strict(A)
[n,n,T] = size(A);
h = 0;
i1 = 0;
i2 = 0;
for t=1:T
  for i=1:n
    for j=i+1:n
      x = A(:,i,t);
      y = A(:,j,t);
      d = .5*sum(abs(x-y));
      % just for reference, to see how quickly we'd catch a problem
      %d = max(abs(x-y));
      if d>h
        i1=i;
        i2=j;
        t0 = t;
        h=d;
      end
      
      % this stricture has the VERY NICE property
      % of not increasing after state collapse
      %d = max(d,max(abs(x-y)));
      % this is the OLD, BAD stricture def.
      % that's the problem that Sinai was so quick to point out
      % in my terminology, this stricture might increase after collapse
    end
  end
end
return