
Re: Is there way to use something like Assuming with the function SIgn?
Posted:
Nov 24, 2012 2:30 AM


Hello
Many thanks.
Ed
On Nov 23, 2012, at 12:01 PM, Bob Hanlon <hanlonr357@gmail.com> wrote:
> "Assuming[assum, expr] evaluates expr with assum appended to > $Assumptions, so that assum is included in the default assumptions > used by functions such as Refine, Simplify, and Integrate." > > list = {1, 2, a, 3}; > > Assuming[a < 0, Simplify[Sign[list]]] > > {1, 1, 1, 1} > > However, more compactly > > Simplify[Sign[list], a < 0] > > {1, 1, 1, 1} > > > Bob Hanlon > > > On Fri, Nov 23, 2012 at 3:25 AM, Eduardo Mendes <emammendes@hotmail.com> wrote: >> 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 >> >> >

