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Dear <span style="caret-color: rgb(50, 49, 48); color: rgb(50, 49, 48); font-family: "Microsoft Yahei UI", Verdana, Simsun, "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 14.666666984558105px; background-color: rgb(255, 255, 255); display: inline !important">Vladimir,</span></div>
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<span style="caret-color: rgb(50, 49, 48); color: rgb(50, 49, 48); font-family: "Microsoft Yahei UI", Verdana, Simsun, "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 14.666666984558105px; background-color: rgb(255, 255, 255); display: inline !important"><br>
</span></div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="caret-color: rgb(50, 49, 48); color: rgb(50, 49, 48); font-family: "Microsoft Yahei UI", Verdana, Simsun, "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 14.666666984558105px; background-color: rgb(255, 255, 255); display: inline !important">Thanks
so much for the quick fix, many thanks again.</span></div>
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<span style="caret-color: rgb(50, 49, 48); color: rgb(50, 49, 48); font-family: "Microsoft Yahei UI", Verdana, Simsun, "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 14.666666984558105px; background-color: rgb(255, 255, 255); display: inline !important"><br>
</span></div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="caret-color: rgb(50, 49, 48); color: rgb(50, 49, 48); font-family: "Microsoft Yahei UI", Verdana, Simsun, "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 14.666666984558105px; background-color: rgb(255, 255, 255); display: inline !important">Best
regards!</span></div>
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<span style="caret-color: rgb(50, 49, 48); color: rgb(50, 49, 48); font-family: "Microsoft Yahei UI", Verdana, Simsun, "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 14.666666984558105px; background-color: rgb(255, 255, 255); display: inline !important">Feng</span></div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>发件人:</b> Vladimir V. Kisil <V.Kisil@leeds.ac.uk><br>
<b>发送时间:</b> 2020年7月27日 22:22<br>
<b>收件人:</b> ginac-list@ginac.de <ginac-list@ginac.de>; GiNaC-devel List <ginac-devel@ginac.de>; Feng Feng <f.feng@outlook.com><br>
<b>主题:</b> Re: [GiNaC-list] 回复: issue about series involving positive symbol</font>
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<div class="PlainText">Dear Feng,<br>
<br>
Thanks for reporting this (rather severe) issue. I am attaching a patch to fix it. It also includes additional GiNaC self-check.<br>
<br>
Best wishes,<br>
Vladimir<br>
<br>
PS. The previous not yet committed bugfix is attached as well.<br>
--<br>
Vladimir V. Kisil <a href="http://www.maths.leeds.ac.uk/~kisilv/">
http://www.maths.leeds.ac.uk/~kisilv/</a><br>
Book: Geometry of Mobius Maps <a href="https://doi.org/10.1142/p835">
https://doi.org/10.1142/p835</a><br>
Soft: Geometry of cycles <a href="http://moebinv.sourceforge.net/">
http://moebinv.sourceforge.net/</a><br>
Jupyter notebooks: <a href="https://github.com/vvkisil/MoebInv-notebooks">
https://github.com/vvkisil/MoebInv-notebooks</a><br>
<br>
________________________________________<br>
From: GiNaC-list <ginac-list-bounces@ginac.de> on behalf of Feng Feng <f.feng@outlook.com><br>
Sent: 27 July 2020 02:23<br>
To: ginac-list@ginac.de<br>
Subject: [GiNaC-list] 回复: issue about series involving positive symbol<br>
<br>
I got a more compact case for this issue, by changing the in1 and in2 to<br>
<br>
ex in1 = reader("t^2/(3*m^2-t*m^2)/2");<br>
ex in2 = reader("-(m^(-2)*(-3+t)^(-1)*t^2/2)");<br>
<br>
sometimes we get the output:<br>
in1-in2 = 0<br>
diff = 0<br>
while, for some other times, we get the output:<br>
in1-in2 = 0<br>
diff = 96*log(1/48)<br>
<br>
it seems that the sign of the log term has been changed.<br>
<br>
Best regards!<br>
Feng<br>
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