( This ( ( ( constituted proof ) ( that ( ( a ( strong ( gravitational field ) ) ) ( ( slows down ) ( time processes ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBD constituted) (NP (NN proof)) (SBAR (IN that) (S (NP (DT a) (JJ strong) (JJ gravitational) (NN field)) (VP (VBZ slows) (PRT (RP down)) (NP (NN time) (NNS processes)))))) (. .)))
This constituted proof that a strong gravitational field slows down time processes.
(ROOT (S (NP (JJ Strong) (JJ gravitational) (NNS fields)) (VP (VBP are) (ADJP (JJ capable) (PP (IN of) (S (VP (VBG altering) (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (NN time) (NN passing))))))))) (. .)))