function printtree(T)
global Tstr
Tstr = [];
subpt(T,1);
Tstr
return


function subpt(T,i)
global Tstr
kids = find(T(i,:));
for j=kids
  fprintf('%d < %d \n',i,j);
  Tstr = [Tstr num2str(i) '<' num2str(j) ';'];
end
for j=kids
  subpt(T,j);
end
return