Limit[ Sign[],x->Infinity ]

*To*: mathgroup at smc.vnet.net*Subject*: [mg27289] Limit[ Sign[],x->Infinity ]*From*: Jack Goldberg <jackgold at math.lsa.umich.edu>*Date*: Fri, 16 Feb 2001 03:58:51 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I give you two examples using ver. 4.0 on a Mac and a unix system. Limit[ Sign[x]*Sign[z],x->Infinity ] yields Sign[z] which is good. Limit[ Sign[x]+Sign[z],x->Infinity] yields an expression too ugly to present to a wide audience, which is bad. Its not a bug since Limit[ Sign[x]+Sign[z],x->Infinity]//FullSimplify yields 1+Sign[z] which is good. I propose the name "buglet" to describe such "features" :-). By the way, I tried some obvious variations on combinations of Sign[z] and Sign[x] and found it pretty hard to predict the output. Happy hunting Jack