Lexical entries.

The lexicon is defined by the predicate lex/2. As an example, the lexical entry `sleeps' could be encoded as:

$$\small\begin{minipage}[t]{.9\textwidth}\begin{verbatim}lex(... ...,agr(3,sg),intrans,l(X,sleep(X)))).\end{verbatim}\end{minipage}$$ (2)

The first argument is the terminal symbol introduced by this lexical category. The second argument is the category (a non-variable term). In cases where a lexical entry introduces a sequence of terminal symbols the first argument is also allowed to be a (non-empty) list of atoms.