parameter. Specifically, it is expected to be a namespace that has the GUI
bindings available. Unfortunately, during the dynamic extent of the
uncaught-exception-handler when a syntax error is raised, this may not be
the case because you get a phase 1 namespace, not a phase 0 one.
So, move the call to display-results to the code that runs the student language
programs and out of the uncaught exception handler.
