RE: Simplification with constraints

*To*: mathgroup at smc.vnet.net*Subject*: [mg72060] RE: [mg72040] Simplification with constraints*From*: "David Park" <djmp at earthlink.net>*Date*: Sun, 10 Dec 2006 04:49:13 -0500 (EST)

Vladimir, What about Eliminate[{expr == b*b + c*c + d*d, a*a + b*b + c*c + d*d == 1}, d] expr == 1 - a^2 David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Vladimir [mailto:vladimir347 at yahoo.com] Suppose we have a constraint: a*a+b*b+c*c+d*d==1 What is the most elegant and general way to simplify any expression considering above constraint for simplification? For (just a simple) example: In[]:=simplify[b*b+c*c+d*d] should give: Out[]=1-a*a -- thanks in advance, Vladimir