sentence1_binary_parse: ( ( A ( dashed arrow ) ) ( ( indicates ( that ( ( ( a class ) ( -LRB- ( ( at ( ( the tail ) ( of ( the arrow ) ) ) ) -RRB- ) ) ) ( ( implements ( the interface ) ) ( -LRB- ( ( at ( ( the head ) ( of ( the arrow ) ) ) ) -RRB- ) ) ) ) ) ) . ) )
sentence1_parse: (ROOT (S (NP (DT A) (JJ dashed) (NN arrow)) (VP (VBZ indicates) (SBAR (IN that) (S (NP (NP (DT a) (NN class)) (PRN (-LRB- -LRB-) (PP (IN at) (NP (NP (DT the) (NN tail)) (PP (IN of) (NP (DT the) (NN arrow))))) (-RRB- -RRB-))) (VP (VBZ implements) (NP (DT the) (NN interface)) (PRN (-LRB- -LRB-) (PP (IN at) (NP (NP (DT the) (NN head)) (PP (IN of) (NP (DT the) (NN arrow))))) (-RRB- -RRB-)))))) (. .)))
sentence1: A dashed arrow indicates that a class (at the tail of the arrow) implements the interface (at the head of the arrow).
sentence2_parse: (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))))))) (. .)))
sentence2: Reversible reactions are indicated by opposite-headed kinds of arrows.