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 >> >> >> >> >> >