Gilles Barthe Julien Forest David Pichardie Vlad Rusu Defining and Reasoning About Recursive Functions: A Practical Tool for the Coq Proof Assistant. 114-129 2006 conf/flops/2006 FLOPS http://dx.doi.org/10.1007/11737414_9 db/conf/flops/flops2006.html#BartheFPR06