Pei He Lishan Kang Daochang Huang Construction of Hoare Triples under Generalized Model with Semantically Valid Genetic Operations. 228-237 2009 ISICA http://dx.doi.org/10.1007/978-3-642-04843-2_25 conf/isica/2009 db/conf/isica/isica2009.html#HeKH09