@@ -465,7 +465,6 @@ For this reason, we also call such accessors \emph{non-atomic}.
The reasons accessors are useful is that they let us talk about ``opening X'' (\eg ``opening invariants'') without having to care what X is opened around.
Furthermore, as we construct more sophisticated and more interesting things that can be opened (\eg invariants that can be ``cancelled'', or STSs), accessors become a useful interface that allows us to mix and match different abstractions in arbitrary ways.
\ralf{This would be much more convincing if we had forward references here to sections describing canellable invariants and STSs.}
