[any body can do exceptional programming]

any: ROOT
body: CHILD OF any
can: CHILD OF body
(any: body ==> NULL), (body: NULL ==> any)
do: CHILD OF can
exceptional: CHILD OF do
(body: can ==> do), (can: do ==> NULL), (do: NULL ==> can)
programming: CHILD OF exceptional

Depth First Traversal:
  1: any(BLACK) c=[NULL, NULL], p=[body]
  2: can(BLACK) c=[NULL, NULL], p=[do]
  3: programming(RED) c=[NULL, NULL], p=[exceptional]
  2: exceptional(BLACK) c=[NULL, programming], p=[do]
  1: do(RED) c=[can, exceptional], p=[body]
  0: body(BLACK) c=[any, do], p=[NULL]