Re: Unacceptable bug in Mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg93538] Re: Unacceptable bug in Mathematica
- From: "Steve Luttrell" <steve at _removemefirst_luttrell.org.uk>
- Date: Thu, 13 Nov 2008 21:07:56 -0500 (EST)
- References: <gfgqf2$dj0$1@smc.vnet.net>
Why do you think Exp[] is not syntactically correct? If you want a syntactically incorrect expression you could try Exp[ instead, where the missing ] causes it to be incomplete in a way that makes it syntactically incorrect. Because Exp[] is a syntactically correct Mathematica expression the Mathematica kernel evaluates it, and produces the result Exp[] (i.e. no change), and simultaneously produces a warning message "Exp::argx: Exp called with 0 arguments; 1 argument is expected.". If you override the default behaviour of Exp[], for instance by using Unprotect[Exp]; Exp[] := myexp[]; Protect[Exp]; then Exp[] will evaluate to myexp[]. -- Stephen Luttrell West Malvern, UK "psycho_dad" <s.nesseris at gmail.com> wrote in message news:gfgqf2$dj0$1 at smc.vnet.net... > The other day, a friend discovered something that may qualify as a > major bug in Mathematica (tested in 6.0.3): > > SyntaxQ["Exp[]"] > > (notice that Exp has no argument) returns > > True !!!! > > According to the documentation: > > SyntaxQ["string"] returns True if the string corresponds to > syntactically correct input for a single Mathematica expression, and > returns False otherwise. > > At least for me Exp[] is not syntactically correct. I expected more > from Mathematica... > > Cheers >