  9.1.4 Signaling and Handling Conditions  The operation of the
condition system depends on the ordering of active applicable
handlers from most recent to least recent.  Each handler is
associated with a type specifier that must designate a subtype
of type condition. A handler is said to be applicable to a
condition if that condition is of the type designated by the
associated type specifier.  Active handlers are established by
using handler-bind (or an abstraction based on handler-bind,
such as handler-case or ignore-errors).  Active handlers can be
established within the dynamic scope of other active handlers.
At any point during program execution, there is a set of active
handlers. When a condition is signaled, the most recent active
applicable handler for that condition is selected from this set.
Given a condition, the order of recentness of active applicable
handlers is defined by the following two rules:  1. Each handler
in a set of active handlers H1 is more recent than every handler
in a set H2 if the