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Is there way to use something like Assuming with the function SIgn?

• To: mathgroup at smc.vnet.net
• Subject: [mg128744] Is there way to use something like Assuming with the function SIgn?
• From: Eduardo Mendes <emammendes at hotmail.com>
• Date: Fri, 23 Nov 2012 03:25:33 -0500 (EST)
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Hello

I was wondering there is something similar to what can be done with Integrate, Reduce and Limit.  Something like

list={1,-2,a,3}

Assuming[a<0,Sign[list]]

Mathematica returns {1,-1,Sign[a],1} and I would like to see something like {1,-1,-1,1}.   Can that be done?

Many thanks

Ed

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  • Re: Is there way to use something like Assuming with the
    • From: Bob Hanlon <hanlonr357@gmail.com>