can be viewed as pure composition and form -- 
(ROOT (S (VP (MD can) (VP (VB be) (VP (VBN viewed) (PP (IN as) (NP (JJ pure) (NN composition) (CC and) (NN form)))))) (: --)))
(ROOT (S (VP (MD ) (VP (VB ) (VP (VBN ) (PP (IN ) (NP (JJ ) (NN ) (CC ) (NN )))))) (: )))