( ( ( ( ( a. ( ( ( 3 ( sigma bonds ) ) and ) ( no ( pi ( bond b. ) ) ) ) ) ( ( ( 3 ( sigma bonds ) ) and ) ( 1 ( pi ( bond c. ) ) ) ) ) ( ( ( 2 ( sigma bonds ) ) and ) ( 1 ( pi ( bond d. ) ) ) ) ) ( ( 2 ( sigma ( bonds ( and ( 2 ( pi bonds ) ) ) ) ) ) 55 ) ) . )
(ROOT (NP (NP (NN a.)) (NP (NP (CD 3) (NN sigma) (NNS bonds)) (CC and) (NP (DT no) (NN pi) (NN bond) (NN b.))) (NP (NP (CD 3) (NN sigma) (NNS bonds)) (CC and) (NP (CD 1) (NN pi) (NN bond) (NN c.))) (NP (NP (CD 2) (NN sigma) (NNS bonds)) (CC and) (NP (CD 1) (NN pi) (NN bond) (NN d.))) (NP (NP (CD 2) (NN sigma) (NNS bonds) (CC and) (CD 2) (NN pi) (NNS bonds)) (NP (CD 55))) (. .)))
a. 3 sigma bonds and no pi bond b. 3 sigma bonds and 1 pi bond c. 2 sigma bonds and 1 pi bond d. 2 sigma bonds and 2 pi bonds 55.
(ROOT (S (NP (DT A) (JJ double) (NN bond)) (VP (VBZ consists) (PP (IN of) (NP (NP (CD one) (NN sigma) (NN bond)) (CC and) (NP (CD one) (NN pi) (NN bond))))) (. .)))