Applying machine learning to the problem of choosing a heuristic to   select the variable ordering for cylindrical algebraic decomposition
  Cylindrical algebraic decomposition(CAD) is a key tool in computational algebraic geometry, particularly for quantifier elimination over real-closed fields. When using CAD, there is often a choice for the ordering placed on the variables. This can be important, with some problems infeasible with one variable ordering but easy with another. Machine learning is the process of fitting a computer model to a complex function based on properties learned from measured data. In this paper we use machine learning (specifically a support vector machine) to select between heuristics for choosing a variable ordering, outperforming each of the separate heuristics. 
Zongyan Huang, Matthew England, David Wilson, James H. Davenport,   Lawrence C. Paulson and James Bridge
cs.SC cs.LG