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

*To*: mathgroup at smc.vnet.net*Subject*: [mg33731] Re: FullSimplify[Abs[Sign[x]],x>=0] equals 1?*From*: "David W. Cantrell" <DWCantrell at sigmaxi.org>*Date*: Wed, 10 Apr 2002 00:49:15 -0400 (EDT)*References*: <a8tsnd$fkm$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Alain Cochard <al2 at noos.fr> wrote: > 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 Is this behavior similar to simplifying x/x to 1, even when x might be 0? Maybe not. Anyway, you might be amused at the result of a typographical error. (I had _intended_ to type logical OR, instead of logical AND.) In[1]:= Simplify[Abs[Sign[x]], x>0 && x==0] Out[1]= 1 Curious! David -- -------------------- http://NewsReader.Com/ -------------------- Usenet Newsgroup Service