( ( The Translator ) ( ( was ( repetitious ( -LRB- ( ( indicated ( by ( ( the ( double-headed arrow ) ) ( in ( the diagram ) ) ) ) ) -RRB- ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNP Translator)) (VP (VBD was) (NP (NP (NNS repetitious)) (PRN (-LRB- -LRB-) (VP (VBN indicated) (PP (IN by) (NP (NP (DT the) (JJ double-headed) (NN arrow)) (PP (IN in) (NP (DT the) (NN diagram)))))) (-RRB- -RRB-)))) (. .)))
The Translator was repetitious (indicated by the double-headed arrow in the diagram).
(ROOT (S (NP (JJ Reversible) (NNS reactions)) (VP (VBP are) (VP (VBN indicated) (PP (IN by) (NP (NP (JJ opposite-headed) (NNS kinds)) (PP (IN of) (NP (NNS arrows))))))) (. .)))
Reversible reactions are indicated by opposite-headed kinds of arrows.