Michele Boreale Complete Algorithms for Algebraic Strongest Postconditions and Weakest Preconditions in Polynomial ODE'S. 442-455 2018 SOFSEM https://doi.org/10.1007/978-3-319-73117-9_31 conf/sofsem/2018 db/conf/sofsem/sofsem2018.html#Boreale18