function dp = dpath(T,i,j)
% T is a directed tree
% all edges (i,j) are of the form i<j

[n,n] = size(T);

try
%Pi = parentseq(T,i);
Pj = parentseq(T,j);
%i0 = max(intersect(Pi,Pj));
%ii0 = find(Pj==i0);
ii0 = find(Pj<=i);
u = max(Pj(ii0));
ii0 = find(Pj==u);
dp = Pj(ii0:end);
%dp = Pj(ii0);
catch
keyboard
end
return




function pseq = parentseq(T,u)
v = u;
el = 0;
pseq = [u];
while v~=1
  el = el+1;
  rents = find(T(:,v));
  if length(rents)~=1
    'bad tree'
    keyboard
  end
  v = rents;
  %pseq(end+1)=v;
  pseq = [v pseq];
  if el > size(T,1)
    'runaway loop'
    keyboard
  end
end
return