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CONSTRAINTS :
Check Syntax
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Overview
This is a new (to nl9701) constraint to check that the proposed fuse is compatible with the current syntactic model. It is required to ensure that the syntactic and semantic models are kept consistent with each other.
Proposal
The constraint is proposed according to the type of fuse and the operator annotated with this fuse type.
Constraints are currently proposed for verb- external, internal, and internal2
(i.e., an external, internal, or internal2 fuse to a verb), as well as
internal path, predicate-nominal, property and preposition fuses.
Implementation
General
Because there may be more than one way in which the u-model may support a particular fuse, there are multiple productions for ascertaining whether a constraint passes or fails. For each possible syntactic configuration that would justify the fuse there is a 'pass' production which fires if that configuration is present and an inverse 'fail' production that fires if any of the pass configuration is not present.
In order to simplify the constraint checking productions a variety of productions are used to annotate the syntactic structure. These annotations include
annotation-to-ip to identify the subject of a possibly multi-tensed
verb, comp-of-verb for predicate nominals, n-cp-verb for
object control verbs, and adjoined-to for adjuncts. Some of these
are actually valued attributes and not annotations, so they can be used
as direct pointers in checking syntactic structure.
N.B. That we recognize that this constraint is a very heavy-handed approach
to guiding semantic interpretation. We use it because it helps constrain
interpretation, but we recognize that other approaches
might be more plausible.
Verb external links
Used to check that a verb external fuse (i.e., agent of an verb) is justified by the u-model.
This constraint passes depending on the value of the ^annotation-to-ip
pointer, which finds the subject of the verb.
Verb internal links
There are 5 ways this constraint currently passes.
- The internal lcs is the complement of the verb. (e.g., ' the man saw the cat'). This is the simplest and most common case.
- The internal object is an action or a state. This is a temporary hack - the constraint doesn't actually look at the syntax but passes if the internal lcs is an action or state.
- The internal object is the subject in a passive sentence.
- The internal object is a subordinate isa link.
- The internal object is an adjoin (for prepositions).
Verb internal2 fuses
This constraint passes when the receiver is the comp2 of the verb.
Properties
This constraint is for checking fuses where the assigner is of category property. There are several ways the constraint can pass because there are several different syntactic categories
that can take property roles. We have broken the conditions into
these: possessive, adverb, adjective, predicate nominals, pp isalinks, and
prepositions. Each of these has its own particular pass and fail conditions.
For more details, see the code.