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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'>Yes, I have the short-circuit logic
operators enabled – this does not make the “implies” operator
a short-circuit operator. As a work-around, I’ve replaced used of
the “implies” operator with judicious use of &&, ||, etc…
in my constraint equations. But I would rather “implies” were
a short-circuit operator itself.</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'>As for setting “Evaluation ends
after first violation,” setting this does prevent GME from
crashing. But, I can’t force the user to set this option.
Since my paradigm won’t work properly unless it is set, it would be nice
if I could in some way configure my paradigm to automatically set this option
for the user. Or, what would be better and easier is if “Evaluation
ends after the first violated priority level” were the default
configuration for GME. I think that’s the setting that makes the
most sense as default anyway.</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'>--Matt</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 style='margin-left:.5in'><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'>-----Original Message-----<br>
<b><span style='font-weight:bold'>From:</span></b> Peter Volgyesi
[mailto:peter.volgyesi@vanderbilt.edu] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, April 22, 2004
9:06 AM<br>
<b><span style='font-weight:bold'>To:</span></b> gme-users<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [gme-users] various
complaints about constraints</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 color=blue face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:blue'>Hi,</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 color=blue face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:blue'>To the short-circuit
evaluation problem: have you tried to enable short-circuit logical operators?
(File/Display Constraints/Settings)</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 color=blue face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:blue'>Also, make sure that
"Evaluation ends after the first violation" is set on this page. </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 color=blue face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:blue'>--</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 color=blue face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:blue'>peter</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<blockquote style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt;
margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<div class=MsoNormal align=center style='margin-left:.5in;text-align:center'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center>
</span></font></div>
<p class=MsoNormal style='margin-right:0in;margin-bottom:12.0pt;margin-left:
.5in'><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>Matthew J. Emerson<br>
<b><span style='font-weight:bold'>Sent:</span></b> Sunday, April 18, 2004 7:16
AM<br>
<b><span style='font-weight:bold'>To:</span></b> gme-users<br>
<b><span style='font-weight:bold'>Subject:</span></b> [gme-users] various
complaints about constraints</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>I don’t think that the
constraint manager really evaluates constraints in the order of their priority.</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>I have two priority-1 constraints
that need to be checked before all others, because if those two constraints
evaluate to false then the other constraints will crash gme. Well, no
matter what priority I make the other constraints, gme crashes. If I
delete the lower-priority constraints, gme does not crash. If I turn my
priority-1 constraints into constraint functions and then call them as part of
the lower-priority constraints as pre-conditions, then gme does not
crash. But I’m going to have a hard time finding every case where I
need to check these pre-conditions and inserting the necessary function calls.
I’m going to miss some and gme is going to soundlessly crash when the
constraint manager goes into an infinite loop.</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>I think that if the constraint
manager would just check my priority-1 constraints first and then stop checking
constraints if they evaluate to false, my life would be much easier.</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Also, if the “implies”
statement used short-circuit evaluation, it would make my life easier.
For instance if you say “A implies B”, and A is false, then
don’t check B.</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Finally, it would be good if some priority
levels beyond level-1 could result in critical evaluations. Assuming that
the constraint manager eventually checks constraints in priority order as I
described above, it would be good to be able to specify an evaluation order
among critical constraints.</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>--Matt </span></font></p>
</blockquote>
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