Isabelle Gnaedig Hélène Kirchner Narrowing, Abstraction and Constraints for Proving Properties of Reduction Relations. 44-67 2007 conf/birthday/2007jouannaud Rewriting, Computation and Proof http://dx.doi.org/10.1007/978-3-540-73147-4_3 db/conf/birthday/jouannaud2007.html#GnaedigK07