Îáõîä äåðåâà ñëåâà - íàïðàâî

  procedure InTree(tree);

   begin

       if Tree = nil then write('Äåðåâî ïóñòî')

       else

           with Tree^ do

             begin

                if left<>nil then InTree(left);

                if right<>nil then InTree(right); 

             end;

 end;