A class creates an instance of a second class and calls a boolean
feature `is_value_required' on it.  The second class has an invariant
that changes the value of a CHARACTER attribute, which affects the
result returned by `is_value_required'.  Code compiles fine when
frozen with all assertions turned on, but when the system is executed
it dies with a segmentation violation.  Finalized code does not die,
but it incorrectly prints "False" instead of "True".

Reported by Manu on November 29, 2002.