Drop 'variability' from glossary (already present in index)

chapters/glossary.tex

@@ -142,21 +142,5 @@ \chapter{Glossary}\label{glossary}
 referenced class, or any of its base classes or constraining types
 transitively at any level. (See \cref{transitively-non-replaceable}.)
 
-\glossaryitem{variability}: property of an expression: one of
-\begin{itemize}
-\item \glossaryitem{continuous}: an expression that may change its value at any
-point in time.
-\item \glossaryitem{discrete}: may change its value only at events during
-simulation.
-\item \glossaryitem{parameter}: constant during the entire simulation, recommended
-to change for a component.
-\item \glossaryitem{constant}: constant during the entire simulation (can be used
-in a package) .
-\end{itemize}
-
-Assignments x := expr and binding equations x = expr must satisfy a
-variability constraint: The expression must not have a higher
-variability than component x. (See \cref{variability-of-expressions}.)
-
 \glossaryitem{vector}: an array where the number of dimensions is 1. (See
 \cref{arrays}.)