A SYNOPSIS OF ROLE AND REFERENCE GRAMMAR 11
mined by the scope principle. In order to be able to capture the differences
between the restrictions on predicates and arguments, on the one hand, and
operators, on the other, Johnson (1987) proposes a formalization of the
LSC in which predicates and their arguments are represented in a distinct
projection from the one representing operators. This formalization he
terms a projection grammar. The general schema of a projection grammar
representation of the LSC is given in Figure 3; the top part is called the
"constituent projection", the bottom the "operator projection". The two
projections are joined through the nucleus, which is the central element in
the clause both in terms of defining the range of possible arguments, on the
one hand, and being the primary entity to which the operator grammatical
categories are oriented, on the other. In the operator projection, the scope
of the operator is indicated by the unit which is the target of the arrow.
Each operator at a given level is so represented, and if there is more than
one, e.g. both tense and IF, then the relative scopes are explicitly indicated.
Examples from English and Japanese are given in Figures 4a,b. In English
