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Re: Bug: symbol recreates itself suddenly

• To: mathgroup at smc.vnet.net
• Subject: [mg86810] Re: Bug: symbol recreates itself suddenly
• From: "Severin Posta" <severin at km1.fjfi.cvut.cz>
• Date: Fri, 21 Mar 2008 01:56:37 -0500 (EST)
• Organization: Czech Technical University
• References: <fro39f$i7v$1@smc.vnet.net> <frqpur$5a5$1@smc.vnet.net>

Unfortunately - it doesn't work (at least in my Win32 6.0 version). Trying 
to do SetAttributes[E,Locked] leads to lock symbol E as Euler constant, not 
to lock it as "Removed" E.
Severin Posta


"Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de> wrote in message 
news:frqpur$5a5$1 at smc.vnet.net...
> Hi,
>
> yes, because E is used in so many mathematical expressions
> like Exp[] that Mathematica can't live without it.
> To avoid such nonsense add
> SetAttributes[E,Locked]
>
> Regards
>   Jens
>
> Severin Posta wrote:
>> It seems to me that after Remove[symbol] some times the symbol is
>> "recreated" without notice. Consider the following example.
>>
>> How to repeat:
>>
>> In[1]:= $Version
>>
>> Out[1]= "6.0 for Microsoft Windows (32-bit) (April 20, 2007)"
>>
>> In[2]:= Unprotect[E]; ClearAttributes[E, {Constant, Protected,
>>
>> ReadProtected}]; Remove[E];
>>
>> In[4]:= ?E
>>
>> During evaluation of In[4]:= Information::notfound: Symbol E not \ found. 
>>  >>
>>
>> In[5]:= Solve[E == 2]
>>
>> Out[5]= {{Global`E -> 2}}
>>
>> (* ?! *)
>>
>> In[6]:= ?E
>>
>> E is the exponential constant e (base of natural logarithms), with \
>> numerical value \[TildeEqual]2.71828. >>
>>
>> (* THIS IS NOT CORRECT ANSWER *)
>>
>>
>>
>> Severin Posta
>>
>>
>>
>>
>>
>