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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Joe,</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>One thing that I notice here is your use
of the ‘==’ comparison operator. Someone else can give you a better
explanation, but in OCL you use ‘=’ for value comparison (OCL does
not have an assignment operator). </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Sandeep</span></font></p>
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10.0pt;font-family:Arial;color:navy'> </span></font></p>
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10.0pt;font-family:Arial;color:navy'> </span></font></p>
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<p class=MsoAutoSig><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>--</span></font></p>
<p class=MsoAutoSig><font
size=3 color=navy face="Times New Roman"><span style='font-size:12.0pt;
color:navy'>Sandeep Neema</span></font></p>
<p class=MsoAutoSig><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>Senior Research Scientist,</span></font></p>
<p class=MsoAutoSig><font
size=3 color=navy face="Times New Roman"><span style='font-size:12.0pt;
color:navy'>Institute</span></font><font color=navy><span style='color:navy'>
of Software</span></font><font color=navy><span style='color:navy'> Integrated
Systems, Vanderbilt University</span></font></p>
<p class=MsoAutoSig><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>Phone: 615-343-9996</span></font></p>
<p class=MsoAutoSig><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>Email: <a
href="mailto:sandeep.k.neema@vanderbilt.edu">sandeep.k.neema@vanderbilt.edu</a></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> gme-users-bounces@list.isis.vanderbilt.edu [mailto:gme-users-bounces@list.isis.vanderbilt.edu] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Joe Porter<br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, August 08, 2006
12:46 PM<br>
<b><span style='font-weight:bold'>To:</span></b> gme-users<br>
<b><span style='font-weight:bold'>Subject:</span></b> [gme-users] Using OCL</span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>My understanding of OCL
is apparently very thin. I have two examples, but I suspect I'm making
the same kind of mistake for both, so here goes:<br>
<br>
In my cute little test case I have the attached class diagram.<br>
<br>
The Level object has an attached constraint to make sure there is only one
Boss-type object in the model:<br>
<br>
self.parts( Boss )->size == 1 <br>
<br>
This is checked for "On new child".<br>
<br>
The Boss object has a constraint as follows, so its "Number"
attribute can only be 1: <br>
<br>
self.Number == 1<br>
<br>
This is checked for "On change attribute"<br>
<br>
For either contraint the warnings show all of the time for the two events,
whether or not the constraint is true. I realize it's most
likely an <br>
OCL syntax issue. Can anyone tell me what I'm missing?<br>
<br>
Thanks,<br>
-Joe</span></font></p>
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