Computing Perspective in Text - Computational Linguistics and Talking Robots - page 217

clause (H'). The constructions 1, 3, and 4 are alike in that they permit an in-
dexical as well as a coreferential interpretation. The construction 2, in contrast,
allows only an indexical interpretation (as shown graphically in 11.3.2); this
more restricted interpretation of construction 2 is indicated by the % marker.
Given that the choice of a pronoun and its form of reference (indexical vs.
coreferential) originate in the speaker, let us consider the DBS graph analyses
of these constructions. We begin with the first two examples of 11.4.1, which
have the pronoun in the higher clause. They share the SRG, but have two
different NAGs and two different surface realizations, (a) and (b):

11.4.2 S UBJECT SENTENCE :P RONOUN IN HIGHER CLAUSE ( MATRIX )

1. LH': That Mary was happy surprised her .
2. H'L: % She was surprised that Mary was happy.
(iii) numbered arcs graphs (NAG)

(i) semantic relations graph (SRG)

surprise a. surprise b. surprise

1 6 3 2

4 6 1

5

happy (Mary)/ça

(Mary)/ça ça

happy happy

2 4 5

3

Mary

Mary Mary

(ii) signature

(iv) surface realization

V

a. 1 2 3 4 5 6

.

V N

That Mary was_happy surprised her

b. 1 2 3 4 5 6

.

N

% She was_surprised that Mary was_happy

For ease of exposition, the node allowing a coreferential as well as an indexical
interpretation is represented as (Mary)/ça . (Mary) represents an address and
stands for the speaker's choice of a coreferential reference (as in 11.3.5), while
ça stands for the choice of an indexical reference (as in 11.3.4).
NAG (a) represents the object of the higher clause as (Mary)/ça , like the
SRG. Consequently, the surface realization may have (i) an indexical or (ii) a
coreferential pronoun interpretation for the hearer. The navigation represented
by NAG (b), in contrast, does not allow a coreferential pronoun interpretation.
Therefore the node is represented as unambiguous ça and the surface realiza-
tion (b) has only an indexical pronoun interpretation, indicated by %.
Next consider the DBS graph analysis of examples 3 and 4 in 11.4.1. As in
11.4.2, they have two different NAGs and two different surface realizations.