15.65.6.19  TREE   - Searches  the current or specified directory tree for
histograms.  For example you have directories //PAWC/X/A, //PAWC/X/B,  and
//PAWC/Y.  You wish to list all histograms in directories X/A and X/B:
     TD:SHOW HIST AREA=//PAWC/X TREE
          or ...
     TD:SET HIST AREA=//PAWC/X
     TD:SHOW HIST TREE