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)*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

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

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