Every u-constructor has to be reconsidered and
every word has to have ^annotation
u-model-success in order for language processing to move on to new words. The
completed operator in the completion space takes care
of these two important operations. And one of the conditions that will lead to the
selection of the completed operator is that the u-constructor be an empty-op
operator (please see the completion space for other
conditions). Hence, whenever the u-constructor is an empty-op operator, two things are
guaranteed:
- the termination of the u-constructor
- the marking of u-model-success on the word the u-constructor is built for
There are two situations in which an u-constructor consists only of an empty-op
operator. Firstly, when NL-Soar parses the first word of a sentence and hence no
links are possible at all.
Secondly, when a new word arrives and after one or several linking and/or snipping,
NL-Soar realizes that the u-model is incomplete. In this case, the new word will not
be marked with u-model-success flag and because of this, another
learn-language operator will be
proposed, which will in turn lead to another u-constructor that consists only of
the empty operator. Since empty operators always result in marking u-model-success
via completion, the word eventually be marked with a u-model-success flag.