while it may not add up to the sum of its parts 
(ROOT (SBAR (IN while) (S (NP (PRP it)) (VP (MD may) (RB not) (VP (VB add) (PRT (RP up)) (PP (IN to) (NP (NP (DT the) (NN sum)) (PP (IN of) (NP (PRP$ its) (NNS parts))))))))))
(ROOT (SBAR (IN ) (S (NP (PRP )) (VP (MD ) (RB ) (VP (VB ) (PRT (RP )) (PP (IN ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (PRP$ ) (NNS ))))))))))