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Re: Plus Behavior Inside a Notation Box?

• To: mathgroup at smc.vnet.net
• Subject: [mg64910] Re: Plus Behavior Inside a Notation Box?
• From: Peter Pein <petsie at dordos.net>
• Date: Tue, 7 Mar 2006 06:12:10 -0500 (EST)
• References: <duh39s$5ui$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Josh schrieb:
> I was trying to set up some aliases using the Notation package and
> noticed some odd behavior when Plus[] is included in the right hand
> side.  I distilled it down to the following, and I'm hoping someone can
> shed some light on this.  The command I set up is:
> 
> Notation[a <=> Plus[b,c] ]
> 
> With the following behavior:
> 
> In[1]:=     b + c
> Out[1]=   a
> 
> In[2]:=     b + c + 1
> Out[2]=   1+b+c
> 
> In[3]:=     b + c + 0
> Out[3]=   a
> 
> Case 1 and 3 work as expected, but case 2 is not.  Any ideas?  The goal
> is to set up aliases for Bessel and Hankel functions in some EM work,
> and it was working very nicely until I hit this 'minor' roadblock.
> 
> Thanks, 
> 
> Josh
> 
The Notation Package seems strange to me. After calling
In[1]:= <<Utilities`Notation`
the cursor jumps between the first an second "<" in the input line.
If I try
In[2]:= Notation[a \[DoubleLongLeftRightArrow] (b + c)]
I get
 From In[2]:=
Notation::noexbtag:The external representation a does not have an embedded \
NotationBoxTag TagBox. The Notation statement Notation[a\
\[DoubleLongLeftRightArrow](b+c)] may not have been entered using the \
palette, or the embedded TagBox may have been deleted. The embedded TagBox \
ensures correct parsing and retention of proper styling and grouping \
information.
Out[2]=
$Failed

This package & me, we can't coexist in the same universe...:-\
I prefer the simple:
In[3]:= b + c + 1 /. b -> a - c
Out[3]= 1 + a