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Re: Types in Mathematica thread

• To: mathgroup at smc.vnet.net
• Subject: [mg62877] Re: Types in Mathematica thread
• From: Jon Harrop <usenet at jdh30.plus.com>
• Date: Tue, 6 Dec 2005 23:12:13 -0500 (EST)
• References: <dn38ft$3la$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Bill Rowe wrote:
> But it is easily added should you want a test for reals using the
> same syntax, e.g.,
> 
> RealQ[x_]:=Element[x,Reals]
> 
> will do the trick quite nicely.

You may also want:

  RealQ[x_] := Element[x,Reals] === True

to guarantee a boolean result, or:

  RealQ[_Real] := True
  RealQ[_] := False

for equivalence with the Head test "_Real", rather than the mathematical
concept of a real number.

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/products/ocaml_for_scientists/chapter1.html

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  • Re: Re: Types in Mathematica thread
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>