Re: Replace and ReplaceAll -- simple application

*To*: mathgroup at smc.vnet.net*Subject*: [mg106123] Re: Replace and ReplaceAll -- simple application*From*: Richard Fateman <fateman at cs.berkeley.edu>*Date*: Sat, 2 Jan 2010 05:04:36 -0500 (EST)*References*: <hhkjce$5aq$1@smc.vnet.net>

Bill Rowe wrote: ... > > Do you have some definition for "bug" other than performance in > a manner different than documented? Yes. > That is, failure of any software to do what a user expects is > certainly not a bug if that is what the software is documented > to do. False. Here's why. By your definition, no program has a bug if the programmer asserts that the program, by virtue of being written in a high-level language, is its own readable documentation. Therefore anything that the program does is documented by its own code and therefore is not a bug. or in the immortal words of Peewee Herman "I meant to do that". > > The key problem here is a novice user of Mathematica might think > of using replacement rules as doing mathematics. Maybe he was confused by the title "Mathematica -- A System for Doing Mathematics", and thought that Mathematica was a system for doing mathematics. That simply > isn't the case. Apparently you thought that Mathematica was "A system for doing rule-based syntactic transformations on FullForm expressions which may or may not correspond to what is displayed" And since replacing one thing with another is > not mathematics, insisting the result makes sense mathematically > simply isn't a realistic expectation. TaDa. I couldn't have expressed it better myself. Insisting that the results of a transformation is mathematically consistent, "isn't a realistic expectation." Which, in my view, demonstrates the existence of a bug. I suppose one could try to determine who is right by a survey, or ask people in the street what they think. RJF > >

**Follow-Ups**:**Re: Replace and ReplaceAll -- simple application***From:*DrMajorBob <btreat1@austin.rr.com>