Re: Why does Reduce work this way ...?

*To*: mathgroup at smc.vnet.net*Subject*: [mg67255] Re: [mg67225] Why does Reduce work this way ...?*From*: "Chris Chiasson" <chris at chiasson.name>*Date*: Wed, 14 Jun 2006 06:29:27 -0400 (EDT)*References*: <200606130507.BAA23801@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

I found Inequality in some output a while ago. I emailed tech support and Tom Zeller pointed me to the following explanation in section A.2.7 of the Mathematica Book: Relational Operators: Relational operators can be mixed. An expression like a > b >= c is converted to Inequality[a, Greater, b, GreaterEqual, c], which effectively evaluates as (a > b) && (b >= c). (The reason for the intermediate Inequality form is that it prevents objects from being evaluated twice when input like a > b >= c is processed.) On 6/13/06, jackgoldberg at comcast.net <jackgoldberg at comcast.net> wrote: > Hi folks, > > This post is related to a previous series of posts about ReplaceAll in a set of inequalities. > I have "reduced" the problem to this unexpected situation: > > In[1] FullForm[-3<=x<=1] > Out[1] LessEqual[-3,x,1] > > In[2] Reduce[-3<=x<=1] > Out[2] -3<=x<=1 > > In[3] FullForm[%2] > Out[3] Inequality[-3, LessEqual, y, LessEqual, 1] > > In[4] Reduce[ LessEqual[-3,x,1] > Out[4] -3 ≤ x ≤ 1 > > In[5] FullForm[%4] > Out[5] Inequality[-3, LessEqual, y, LessEqual, 1] > > This defies my understanding. What is qoing on with Reduce? > > Jack > > -- http://chris.chiasson.name/

**References**:**Why does Reduce work this way ...?***From:*jackgoldberg@comcast.net