Nikolaj Bjørner Anca Browne Zohar Manna Automatic Generation of Invariants and Intermediate Assertions. 49-87 1997 173 Theor. Comput. Sci. 1 db/journals/tcs/tcs173.html#BjornerBM97 http://dx.doi.org/10.1016/S0304-3975(96)00191-0