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From: gbooch@ajpo.sei.cmu.edu (Grady Booch)
Newsgroups: comp.object
Subject: Re: Visibility in Booch's book
Message-ID: <717@ajpo.sei.cmu.edu>
Date: 25 Oct 90 01:15:24 GMT
References: <21243@well.sf.ca.us>
Reply-To: gbooch@ajpo.sei.cmu.edu (PUT YOUR NAME HERE)
Distribution: comp
Organization: Ada Joint Program Office
Lines: 9

The reverse is indeed true (a few others have pointed this out, and the bug 
will be fixed in the next printing). I and my copyeditor
apparently missed this reversal.

if object X of class A sends a message to object Y of B, then it must
be the case that class A in some manner has visibility to class B. this
visibility may be achieved via a using relationship, or via an inheritance relationship.

egb