Non linear System of inequalities

*To*: mathgroup at smc.vnet.net*Subject*: [mg57238] Non linear System of inequalities*From*: azzam_maraee at hotmail.com*Date*: Sat, 21 May 2005 02:40:50 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I need a help at solving Non linear System of inequalities in tree variabels or more for example: xy<=r<=2xy xz<=r<=2xz yz<=r<=2yz and so on... my Non linear System of inequalities represent the constraints at at some problem which I search (consistency of a model). is there any material or sites which may help me? I will apreciate any help.