Lexical Functional Grammar - Personal Pages Index

a theory of constructive case, according to which a casemarked phrase places
constraints on its f-structure environment that determine its grammatical function
in the sentence. This treatment supplants the traditional treatment of
obliques in terms of the PCASE feature.
3.2 Functional descriptions
As with c-structures, we draw a sharpdistinction between f-structures and their
descriptions. The set of f-structure constraints associated with the analysis of
some sentence is called a functional description or f-description.
To refer to the value of a feature in some f-structure, we use an expression
like the following:
(18) Reference to the value of the TENSE feature in f:
(f TENSE)
This expression refers to the value of the TENSE feature in the f-structure f. If
we want to specify the value of that feature, we use an expression like:
(19) (f TENSE) = PAST
This defining equation specifies that the feature TENSE in the f-structure f
has the value PAST.
We can also specify that a feature has a particular f-structure as its value.
The expression in (20) specifies that the value of the SUBJ feature in f is the
f-structure g:
(20) (f SUBJ) = g
Somefeaturestakeastheirvalueasetoffunctionalstructures. Forexample,
since any number of adjuncts can appear in a sentence, the value of the feature
ADJ is a set. We can specify that an f-structure h is a member of the ADJ set
with the following constraint, using the set-membership symbol ∈:
(21) h ∈ (f ADJ)
The constraints discussed so far are called defining constraints, since they
define the required properties of a functional structure. An abbreviated f-
description for a sentence like David sneezed is:
(22) (f PRED) = ‘SNEEZE〈SUBJ〉’
(f TENSE) = PAST
(f SUBJ) = g
(g PRED) = ‘DAVID’
This f-description holds of the following f-structure, where the f-structures are
annotated with the names used in the f-description (22):
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