( Luminosity ( , ( ( Distance ( , ( Size ( A -RRB- ) ) ) ) ( ( Magnitudes etc. ) . ) ) ) )
(ROOT (S (ADVP (RB Luminosity)) (, ,) (NP (NNP Distance) (, ,) (NNP Size) (NNP A) (-RRB- -RRB-)) (VP (VBZ Magnitudes) (NP (FW etc.))) (. .)))
Luminosity, Distance, Size A) Magnitudes etc.
(ROOT (S (NP (NNP Distance)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN magnitude) (CC or) (NN size)) (PP (IN of) (NP (NP (NN displacement)) (PP (IN between) (NP (CD two) (NNS positions))))))))) (. .)))