Re: Re: When is a List not a List?
- To: mathgroup at smc.vnet.net
- Subject: [mg90996] Re: [mg90956] Re: [mg90947] When is a List not a List?
- From: DrMajorBob <drmajorbob at att.net>
- Date: Sat, 2 Aug 2008 03:27:14 -0400 (EDT)
- References: <200807310656.CAA07700@smc.vnet.net>
- Reply-to: drmajorbob at longhorns.com
But I obviously DO understand those facts. I illustrated them in detail. I also illustrated the fact that Plot has a Line for each branch, so each COULD be colored differently, if Plot were built to do so. I also agreed with your basic point that it's fruitless to call this a "quirk", after all these years. Bobby On Fri, 01 Aug 2008 15:44:12 -0500, Andrzej Kozlowski <akoz at mimuw.edu.pl> wrote: > On 1 Aug 2008, at 21:18, DrMajorBob wrote: > >> In light of all that, in what way have the rest of us failed to >> understand "a bit of mathematics"? > > Te bit of mathematics (and computer algebra) you clearly do not > understand is the very basic fact when you solve many kinds of algebraic > equations with symbolic parameters you inevitably introduce parasite > solutions. When you use numeric parameters Solve can verify which of > theses are correct. The rest of the discussion is totally besides the > point, and so is using Reduce (for example, because one can easily come > up with equations that Reduce will not manage). > The example was meant to illustrate the very trivial and elementary fact > that the world is full of functions with parameters that can be > evaluated pointwise (once numeric parameters have been substituted) but > cannot be evaluated by Evaluate. This is so basic and there are so many > examples of it that I do not see any point in discussion this farther. > > Andrzej Kozlowski > > -- DrMajorBob at longhorns.com