( ( Mercury Closest ) ( ( planet ( to ( the sun ) ) ) . ) )
(ROOT (S (NP (NNP Mercury) (NNP Closest)) (VP (VBZ planet) (PP (TO to) (NP (DT the) (NN sun)))) (. .)))
Mercury Closest planet to the sun.
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (ADJP (ADJP (JJS closest)) (PP (TO to) (NP (DT the) (NN sun))))) (. .)))