Update len() to expect new format for funcall subtrees.  Sum.ttr and fact.ttr now run properly.
Update len() to expect new format for funcall subtrees.  Sum.ttr and
fact.ttr now run properly.

IanFinlayson/tetra,IanFinlayson/tetra,IanFinlayson/tetra,IanFinlayson/tetra,IanFinlayson/tetra,IanFinlayson/tetra