Frédéric Vogels Bart Jacobs 0002 Frank Piessens A Machine Checked Soundness Proof for an Intermediate Verification Language. 570-581 2009 SOFSEM http://dx.doi.org/10.1007/978-3-540-95891-8_51 conf/sofsem/2009 db/conf/sofsem/sofsem2009.html#VogelsJP09