Interactive Theorem Proving 9th International Conference, ITP 2018, Held as Part of the Federated Logic Conference, FloC 2018, Oxford, UK, July 9-12, 2018, Proceedings - Avigad, Jeremy; Avigad, Jeremy; Mahboubi, Assia; Mahboubi, Assia (Springer International Publishing : Imprint: Springer, 2018)