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Re: Replacement Rule with Sqrt in denominator
*To*: mathgroup at smc.vnet.net
*Subject*: [mg114324] Re: Replacement Rule with Sqrt in denominator
*From*: Murray Eisenberg <murray at math.umass.edu>
*Date*: Wed, 1 Dec 2010 02:10:45 -0500 (EST)
It's not a bug (and not really a "feature", either):
FullForm[1/Sqrt[x]]
Power[x,Rational[-1,2]]
Thus there is no "Sqrt[x] really in 1/Sqrt[x] (the latter being just a
quick input form), just as there is no "I" in 1+2I.
On 11/30/2010 4:05 AM, Richard Fateman wrote:
> On 11/20/2010 3:11 AM, kj wrote:
>
>>
>> I don't know a way to write the replacement rule so that it works
>> for both Sqrt[x] and 1/Sqrt[x], but maybe someone else does.
>>
>> ~kj
>>
> See
> www.cs.berkeley.edu/~fateman/papers/better-rules.pdf
>
> which describes how one can automatically produce rules that overcome
> this bug in Mathematica. oops. I mean rules that overcome this
> "feature" in Mathematica.
>
> RJF
>
>
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305
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