Cristiano Calcagno Dino Distefano Peter W. O'Hearn Hongseok Yang Compositional shape analysis by means of bi-abduction. 289-300 2009 POPL http://doi.acm.org/10.1145/1480881.1480917 conf/popl/2009 db/conf/popl/popl2009.html#CalcagnoDOY09