Re: Bug: symbol recreates itself suddenly
- To: mathgroup at smc.vnet.net
- Subject: [mg86809] Re: Bug: symbol recreates itself suddenly
- From: "Severin Posta" <severin at km1.fjfi.cvut.cz>
- Date: Fri, 21 Mar 2008 01:56:25 -0500 (EST)
- Organization: Czech Technical University
- References: <9457525.1205860522819.JavaMail.root@m08> <frqpu5$59m$1@smc.vnet.net>
This is definitely NOT the correct answer. The correct answer is (should be) "Symbol E not found." By all means this is really a bug. It has far-reaching consequences. Using symbol E afterwards can lead to mistakes because Mathematica thinks (suddenly!) this is again Euler constant, not general symbol. Please don't ask why am I doing this. This is not forbidden according to manual - and it worked in 4.0, 5.0, 5.2 versions. It should work in 6.0 either. (Or it should be documented.) Severin Posta "DrMajorBob" <drmajorbob at bigfoot.com> wrote in message news:frqpu5$59m$1 at smc.vnet.net... > "In[6]:= ?E > > E is the exponential constant e (base of natural logarithms), with \ > numerical value \[TildeEqual]2.71828. >> > > (* THIS IS NOT CORRECT ANSWER *)" > > Oh yes, it certainly IS the correct answer. > > Why do you want to Remove built-in constants? (Regardless of whether it > might or might not "work" to do so?) > > Bobby > > On Tue, 18 Mar 2008 04:50:49 -0500, Severin Posta > > <severin at km1.fjfi.cvut.cz> 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 >> >> >> >> >> >> > > > > -- = > > DrMajorBob at longhorns.com >