Next: Clause Type
Up: Extraction and Inversion
Previous: Inversion, Part 1
displ-const:
Possible values: [set1: +], [set1: -]
In the previous section, we saw how inversion is
triggered using the invlink,
inv,
wh
features. Inversion
involves movement of the verb from V to C. This movement process is
represented using the displ-const
feature
which is used to simulate Multi-Component TAGs.30.1 The sub-value set1 indicates the inversion
multi-component set; while there are not currently any other uses of
this mechanism, it could be expanded with other sets receiving
different set values.
The displ-const
feature is used to ensure
adjunction of two trees, which in this case are the auxiliary
tree corresponding to the moved verb (S adjunct) and the auxiliary tree
corresponding to the trace of the moved verb (VP adjunct). The following
equations are used:
(578)0(578
- (579)
- Sr.b:displ-const set1
(579)0(579
- (580)
- S.t:displ-const set1
(580)0(580
- (581)
- VP.b:displ-const set1 V.t:displ-const set1
(581)0(581
- (582)
- V.b:displ-const set1
(582)0(582
- (583)
- Sr.b:displ-const set1 VP.t:displ-const set1
XTAG Project
http://www.cis.upenn.edu/~xtag