equivalent to Mathematica's Reduce?



Reduce takes an equation or an  inequality and tries to simplify, 
eliminating quantifiers

e.g.
Reduce[x^2 + y^2 < 1, {x, y}] -->     -1 < x < 1 && -Sqrt[1 - x^2] < y < 
Sqrt[1 - x^2]

Has anyone written something like this?

It is related to solve, eliminate, ..

How does solve and reduce differ?
  From the documentation..


The general question of whether a set of equations has any consistent 
solution is quite a subtle one. For example, for most values of a, the 
equations {x==1,x==a} are inconsistent, so there is no possible solution 
for x. However, if a is equal to 1, then the equations do have a 
solution. Solve is set up to give you generic solutions to equations. It 
discards any solutions that exist only when special constraints between 
parameters are satisfied.

If you use Reduce instead of Solve, Mathematica will however keep all 
the possible solutions to a set of equations, including those that 
require special conditions on parameters.


RJF