( Mercury ( ( is ( ( the smallest ) ( of ( ( the planets ) ( in ( our ( solar system ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (NP (NP (DT the) (JJS smallest)) (PP (IN of) (NP (NP (DT the) (NNS planets)) (PP (IN in) (NP (PRP$ our) (JJ solar) (NN system))))))) (. .)))
Mercury is the smallest of the planets in our solar system.
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (NP (NP (DT the) (JJS smallest) (NN planet)) (PP (IN in) (NP (PRP$ our) (JJ solar) (NN system))))) (. .)))