Re: FullSimplify[Abs[Sign[x]],x>=0] equals 1?

*To*: mathgroup at smc.vnet.net*Subject*: [mg33730] Re: [mg33691] FullSimplify[Abs[Sign[x]],x>=0] equals 1?*From*: BobHanlon at aol.com*Date*: Wed, 10 Apr 2002 00:49:13 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

In a message dated 4/9/02 1:29:40 AM, al2 at noos.fr writes: >Is the following behavior normal? > > >In[1]:= Simplify[Abs[Sign[x]],x>=0] > >Out[1]= Abs[Sign[x]] > >In[2]:= FullSimplify[Abs[Sign[x]],x>=0] > >Out[2]= 1 > >In[3]:= $Version > >Out[3]= 4.1 for Sun Solaris (November 8, 2000) > > >In this case I would have expected FullSimplify to give the save >answer as Simplify, as I was (naively?) assuming Abs[Sign[0]] equals >zero. What am I missing? (Note I get the same output >for Version 4.0 for Linux (July 22, 1999).) > I have the same problem on a Mac with OS X $Version 4.1 for Mac OS X (November 5, 2001) Simplify[Abs[Sign[x]],x>=0] Abs[Sign[x]] FullSimplify[Abs[Sign[x]],x>=0] 1 Bob Hanlon Chantilly, VA USA