Lukas Bulwahn Alexander Krauss Florian Haftmann Levent Erkök John Matthews Imperative Functional Programming with Isabelle/HOL. 134-149 2008 TPHOLs http://dx.doi.org/10.1007/978-3-540-71067-7_14 conf/tphol/2008 db/conf/tphol/tphol2008.html#BulwahnKHEM08