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Re: problem with EvenQ

• To: mathgroup at smc.vnet.net
• Subject: [mg105947] Re: [mg105923] problem with EvenQ
• From: Murray Eisenberg <murray at math.umass.edu>
• Date: Sun, 27 Dec 2009 02:26:15 -0500 (EST)
• Organization: Mathematics & Statistics, Univ. of Mass./Amherst
• References: <200912270006.TAA12116@smc.vnet.net>
• Reply-to: murray at math.umass.edu

That seems to be an incomplete implementation of FindInstance.  But the 
following will work, albeit with the very unsurprising result shown:

    FindInstance[2 y < 100 && Mod[y, 2] == 0, {y}, Integers]
{{y->0}}

    (* for a less unsurprising result: *)
    FindInstance[2 y < 100 && Mod[y, 2] == 0 && y > 0, {y}, Integers]
{{y->48}}

dvholten wrote:
> Hi folks,
> i puzzled all afternoon, but couldnt get this one solved:
> what is the proper way of using EvenQ[] within FindInstance[] ?
> I cant use it like
>     FindInstance[ y*2 < 100 && EvenQ[y], {y}, Integers ]
> or even
>     FindInstance[ EvenQ[y], {y}, Integers ]
> 
> Actually, the expression used in FindInstance is much more complex,
> but i condensed the problem to be EvenQ[] - i expect some kind of 
> special notation to help here.
> 
> thanks
> dvh
> 

-- 
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

• Follow-Ups:
  • Re: Re: problem with EvenQ
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>

• References:
  • problem with EvenQ
    • From: dvholten <info@dvholten.de>