Re: quadratic multiplication

*To*: mathgroup at smc.vnet.net*Subject*: [mg84274] Re: quadratic multiplication*From*: dh <dh at metrohm.ch>*Date*: Mon, 17 Dec 2007 03:04:06 -0500 (EST)*References*: <fk2v35$n96$1@smc.vnet.net>

Hi, we may create a rule that sets all products of u^s to zero: mem[y_]:=MemberQ[{u1,u2,u3,u4,u5,u6},y]; rules={y1_ y2_/;mem[y1]&&mem[y2]->0,y_^_/;mem[y]->0}; here is an example: c1 u1+c2 u2+ c15 u1 u5 + c146 u1 u4 u6 /. rules hope this helps, Daniel KFUPM wrote: > Dear all > > I have a very large expression which involves the multiplication of > these variables: > > var ={u1,u2,u3,u4,u5,u6} with some other constants. In the expression, > i want to suppress any quadratic or higher order multiplication of > these varibles , e.g u1*u5 or u1*u4*u6 should be zero. And since, my > expression is huge, i want to do this automatically. Any help in this > regard is highly appreciated. > > > Sincererly yours, > > HMQ >