A comparison of three heuristics to choose the variable ordering for CAD
  Cylindrical algebraic decomposition (CAD) is a key tool for problems in real algebraic geometry and beyond. When using CAD there is often a choice over the variable ordering to use, with some problems infeasible in one ordering but simple in another. Here we discuss a recent experiment comparing three heuristics for making this choice on thousands of examples. 
Zongyan Huang, Matthew England, David Wilson, James H. Davenport and   Lawrence C. Paulson
cs.SC