meaning of PNZ?

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Hi - Here's a short session in which I differentiate a function containing sign(x) amongst other things.  Does anyone know what the PNZ(...) notation means?  Many thanks for any insight into this.

Cheers,

Dave Holmgren

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Microsoft(R) Windows NT(TM)
(C) Copyright 1985-1996 Microsoft Corp.

e:\emacs-20.7\bin>cd e:\
cd e:\

E:\>maxima.bat
maxima.bat

E:\>set MAXIMA_DIRECTORY=c:\maxima 

E:\>c:\maxima\src\saved_maxima.exe -dir c:\maxima\src\  
GCL (GNU Common Lisp)  Version(2.3.6) Tue Dec  5 16:55:56  2000
Licensed under GNU Library General Public License
Contains Enhancements by W. Schelter
Maxima 5.5 Tue Dec 5 16:55:33 2000 (with enhancements by W. Schelter).
Licensed under the GNU Public License (see file COPYING)
(C1) f(x):=1/2+sign(x)*(1/2-1/4*exp(-abs(x))*(2+abs(x)));

                     1                 1  1
(D1)      f(x) := - + SIGN(x) (- - - EXP(- ABS(x)) (2 + ABS(x)))
                     2                 2  4
(C2) diff(f(x),x);

                                - ABS(x)                   - ABS(x)
                        x %E   (ABS(x) + 2)  x %E
(D2)          PNZ (------------------------- - ------------)
                                 4 ABS(x)     4 ABS(x)
(C3) quit();


E:\>
E:\>exit
exit

Process shell finished


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<DIV><FONT face=Arial size=2>Hi - Here's a short session in which I 
differentiate a function containing sign(x) amongst other things.&nbsp; Does 
anyone know what the PNZ(...) notation means?&nbsp; Many thanks for any insight 
into this.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>Cheers,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>Dave Holmgren</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>----</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>Microsoft(R) Windows NT(TM)<BR>(C) Copyright 
1985-1996 Microsoft Corp.</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>e:\emacs-20.7\bin&gt;cd e:\<BR>cd e:\</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>E:\&gt;maxima.bat<BR>maxima.bat</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>E:\&gt;set MAXIMA_DIRECTORY=c:\maxima </FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>E:\&gt;c:\maxima\src\saved_maxima.exe -dir 
c:\maxima\src\&nbsp; <BR>GCL (GNU Common Lisp)&nbsp; Version(2.3.6) Tue 
Dec&nbsp; 5 16:55:56&nbsp; 2000<BR>Licensed under GNU Library General Public 
License<BR>Contains Enhancements by W. Schelter<BR>Maxima 5.5 Tue Dec 5 16:55:33 
2000 (with enhancements by W. Schelter).<BR>Licensed under the GNU Public 
License (see file COPYING)<BR>(C1) 
f(x):=1/2+sign(x)*(1/2-1/4*exp(-abs(x))*(2+abs(x)));</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=Arial 
size=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
1&nbsp;&nbsp;1<BR>(D1) &nbsp;&nbsp;&nbsp;&nbsp; f(x) := - + SIGN(x) (- - - EXP(- 
ABS(x)) (2 + 
ABS(x)))<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
2&nbsp;&nbsp;4<BR>(C2) diff(f(x),x);</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=Arial 
size=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
&nbsp;&nbsp; - 
ABS(x)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
&nbsp;- 
ABS(x)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
x %E&nbsp;&nbsp; (ABS(x) + 2)&nbsp; x %E<BR>(D2) 
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; PNZ (------------------------- 
- 
------------)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
4 ABS(x)&nbsp;&nbsp;&nbsp;&nbsp; 4 ABS(x)<BR>(C3) quit();</FONT></DIV>
<DIV>&nbsp;</DIV><FONT face=Arial size=2>
<DIV><BR>E:\&gt;<BR>E:\&gt;exit<BR>exit</DIV>
<DIV>&nbsp;</DIV>
<DIV>Process shell finished<BR></FONT></DIV></BODY></HTML>

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