Ch3, Ex9

declare Append
local IterReverse MyAppend in
   fun {MyAppend L1 L2}
      case L1 of nil then L2
      [] X|Y then {MyAppend Y X|L2}
      end
   end
   fun {IterReverse X Y}
      case X of nil then Y
      [] X1|X2 then {IterReverse X2 X1|Y}
      end
   end
   fun{Append Xs Ys}
      %{Browse {IterReverse Xs nil}}
      {MyAppend {IterReverse Xs nil} Ys}
   end
end
%Test
{Browse {Append [1 2 5 6 7] [3 4]}}