This includes a variety of syntactic phenomena, such as
co-referentiality (in e.g. control structures), cross-reference
(or substitution), ellipsis, control, traces and syntactic
discontinuity. In table 8,
an example from the Penn Treebank,
co-referentiality is marked by
indices. The subject
position of the infinitive phrase to go has the same index
-- 8 -- as the subject of the conditional clause (NP-SBJ-8 you).
(S (NP-SBJ You) |
(VP can |
(VP leave |
(SBAR-ADV if |
(S (NP-SBJ-8 you) |
(ADVP really) |
(VP want |
(S (NP-SBJ *-8) |
(VP to |
(VP go))))))))) |