Compositional Semantics - Computational Linguistics and Talking Robots - page 138

slot of the is proplet is canceled. In line 2, the two occurrences of the substi-
tution value v_1 are replaced by another substitution value, n_1 , provided by
the determiner. Also, the values indef sg are added to the sem slot of the is
proplet. In line 3, the two occurrences of the substitution value n_1 are re-
placed by the core value of the doctor proplet, which is then discarded. The
result is a doctor proplet with the core attribute verb .
The doctor proplet is opaque insofar as the core attribute verb has the nom-
inal value doctor and the sem attribute mixes the nominal values indef sg
with the verbal value pres .The Julia proplet is opaque in that its fnc attribute
has the nominal value doctor . The signature, however, shows an apparently
transparent N / V structure:

7.5.6 DBS GRAPH ANALYSIS OF Julia is a doctor.

(i) semantic relations graph (SRG) (iii) numbered arcs graph (NAG)

doctor doctor

1

2

Julia

Julia

(ii) signature

V

(iv) surface realization

1 2

is_a_doctor_

.

N

Julia

Thus, a content construction may be opaque even if the signature appears to be
transparent. Traversal of arc 1 realizes Julia , while traversal of arc 2 realizes
is_a_doctor_ . , utilizing the values be, indef, sg, decl ,and doctor of the
doctor proplet (see result of 7.5.5).
Similarly, the subject-predicate relation in the English copula construction
Fido is hungry is N V(trans-

parent) based on the content proplets. Here the change from the lexical core
attribute A to the content core attribute V likewise originates in the function
word is into which the lexical core value, i.e., hungry , is absorbed. Because
the DBS representation of semantic relations of structure applies to the level
of content, the PoS participating in these semantic relations are determined by
the core attributes of the content (and not the lexical) proplets.

/ A (opaque) based on the lexical proplets, but N /

7.6 Possible and Actual Semantic Relations of Structure

Intrapropositionally, the number of elementary signatures consisting of the
nodes N, V, and A and the lines “