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Re: Replace and ReplaceAll -- simple application

  • To: mathgroup at smc.vnet.net
  • Subject: [mg106111] Re: Replace and ReplaceAll -- simple application
  • From: Noqsi <jpd at noqsi.com>
  • Date: Fri, 1 Jan 2010 05:38:50 -0500 (EST)
  • References: <200912270006.TAA12080@smc.vnet.net> <hh72dp$kud$1@smc.vnet.net>

On Dec 31, 1:13 am, Richard Fateman <fate... at cs.berkeley.edu> wrote:

> But when the weight of all mathematical obviousness is on one side, and
> the developers could fix a bug but simply refuse to do so, then that is
> simply stubbornness.

I don't see any "mathematical obviousness" to the idea that syntactic
replacements involving "I" will have sane mathematical consequences.
"I" is explictily present only in a subset of complex number
representations. "Root[#1^5 + 1 &, 2]" is a perfectly reasonable
complex constant, but syntactic replacement of "I" with "-I" will not
produce its conjugate. For mathematically aware manipulations, you
need mathematically aware functions, "Conjugate" in this case.
Expecting to do this syntactically seems as silly to me as expecting
"x/.6->5" to yield "5x/6", or "32/.3->4" to yield "42".



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