Re: Is there way to use something like Assuming with the

*To*: mathgroup at smc.vnet.net*Subject*: [mg128760] Re: Is there way to use something like Assuming with the*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Sat, 24 Nov 2012 02:25:26 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20121123082533.A76536891@smc.vnet.net>

"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 at 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 > >

**References**:**Is there way to use something like Assuming with the function SIgn?***From:*Eduardo Mendes <emammendes@hotmail.com>