Hi Doug:

thank you for pointing this out. I followed your advice 
From dougo@ccs.neu.edu Sun Jun 20 18:00:40 1999
From: Doug Orleans <dougo@ccs.neu.edu>
Date: Sun, 20 Jun 1999 18:00:37 -0400 (EDT)
To: Karl Lieberherr <lieber@ccs.neu.edu>
Cc: jayantha@ccs.neu.edu
Subject: Re: safe collections

Karl Lieberherr writes:
 > Hi Doug and Josh:
 > 
 > I have a question about:
 > 
 > /course/com3362/sp99/DJ/nested-bus-routes-wysiwyg
 > 
 > file: output
 > 
 > why is the link from Bus =                   <fpassengers> PersonList.
 > included in the traversal graph?
 > 
 > I was under the impression that arrays are typesafe and that the
 > system does not traverse them if there is no chance of succeeding
 > based on the strategy.

The leg "BusStop -> Person bypassing {BusRoute,BusStop,Person}"
includes the path

  BusStop,waiting,MyVector,elements,Bus,passengers,PersonList,persons,Person

because the MyVector is not typed.  If BusStop.waiting were instead a
PersonList, I think you'd get what you want.

--Doug