Aleksandar Nanevski Greg Morrisett Avraham Shinnar Paul Govereau Lars Birkedal Ynot: dependent types for imperative programs. 229-240 2008 ICFP http://doi.acm.org/10.1145/1411204.1411237 conf/icfp/2008 db/conf/icfp/icfp2008.html#NanevskiMSGB08