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More "Logical" functions?

  • To: mathgroup at
  • Subject: [mg4144] More "Logical" functions?
  • From: sherod at boussinesq.Colorado.EDU (Scott Herod)
  • Date: Fri, 7 Jun 1996 02:08:11 -0400
  • Organization: University of Colorado at Boulder
  • Sender: owner-wri-mathgroup at

I often find myself trying to solve big sets of polynomial equations.
I realize that there are Groebner basis packages for use in this but
many times I can get by with Reduce and Solve.  My problem is this:

Often I get results like

   {{ x -> 0 },  {x -> 0, y -> 5 },  {x -> 0, z -> -2}, ... }

where {x -> 0} is common to all of the terms.  I would like to be able
to factor out the x=0 from each equation.  I don't need to see everything
else if x has to be zero anyway.

Currently I'm doing a LogicalExpand[results && x != 0] to see the cases
where x does not have to be zero, but something to factor the x -> 0
would be nicer.

Does anyone know of an existing package do Logical expression operations?

Scott Herod
(sherod at


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