On Fri, Aug 22, 2008 at 12:23 AM, Masashi Shimbo <shimbo at is.naist.jp> wrote: > It is easy when << returns self: > > A << (B << C) \ > << (D << E) > > This makes A with two children B and C each with a > If you want a path (tree without branches), > you can still do > > A << (B << (C << D))) Doh! Of course. It has to return self. T.