Iksoon Hwang Mounir Lallali Ana R. Cavalli Dominique Verchère Modeling, Validation, and Verification of PCEP Using the IF Language. 122-136 2009 FMOODS/FORTE http://dx.doi.org/10.1007/978-3-642-02138-1_8 conf/forte/2009 db/conf/forte/forte2009.html#HwangLCV09