The remove operator enforces the limit of two non-discriminable items
on the A/R set. A number of different strategies are possible, including
less-recent, main-verb, and pronoun, and close-off. The less-recent strategy
is the default strategy; the others have their own more specific proposal
conditions.
Operator Proposal:
The remove operator, type less-recent, is immediately proposed when
the ar-set problem space is created. Other
types may also be proposed.
Operator Application:
When the remove operator is selected for application, it is first
elaborated with the items (and their position on the A/R set) to be removed.
This is done with a number of
elaboration productions categorized by the type of the remove operator. For
example, less-recent types have elaboration productions to identify
the less recent item, including special productions to choose among polysemous
items (which have the same word-id). The pronoun type finds inactive
pronouns and removes them. The main-verb type removes the main
verb if the auxiliary sense is active. The close-off type is a first
stab at some reasoning about when constituents can be considered closed to semantic modification or elaboration.
In the second stage, a general production fires to remove all the items on
the operator from the position they were in on the A/R set.