Re: Simplify with NestedLessLess?

*To*: mathgroup at smc.vnet.net*Subject*: [mg106537] Re: [mg106487] Simplify with NestedLessLess?*From*: "David Park" <djmpark at comcast.net>*Date*: Fri, 15 Jan 2010 03:22:18 -0500 (EST)*References*: <23979164.1263466810832.JavaMail.root@n11>

Why should it Simplify d? NestedLessLess has no built-in meaning. And even if it did mean that b << a there is no reason that Mathematica should still set b to zero. It doesn't even know if a and b are real positive. You will have to set it to zero yourself. d /. b -> 0 a For more complicated expressions you might have to use Limit. David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: dbird [mailto:dbird at ieee.org] Please excuse if this has been answered before, but I can't find it. Is there some way to do a Simplify with assumptions using a NestedLessLess or something similar? For example: d=a+b Simplify[d,NestedLessLess[a,b]] Answer is: a+b Answer should be: b Thanks, Dave