\doc{Keywords}
\ref{keywords}
\ref{by}
\ref{in}
\ref{to}
\ref{with}
\ref{reserved-words}

The keywords \fq{by}, \fq{else}, \fq{if}, \fq{in}, \fq{then}, \fq{when}, and
\fq{yield} cannot be used as identifiers for sorts, variables, or operators.
\p
The keywords \fq{to} and \fq{with} cannot be used as
\dlink{../misc/name}{names} for facts, or as components of a name pattern.
\p
LP reserves other words (\f{ac}, \f{commutative}, \f{depth}, \f{on}, \f{sort},
\f{using} and \f{well}) in certain contexts within facts and conjectures, but
does not prohibit their use as identifiers.