Abstracts of Invited Talks -- Testing, Fixing and Proving with Contracts -- Mind the Gap: At the Crossroads of Design, Implementation and Foundations -- Reasoning about C Concurrency and Compilers -- Accepted Papers -- Scalable incremental test-case generation from large behavior models -- Test Case Generation for Concurrent Systems Using Event Structures -- Fast Model-Based Fault Localisation with Test Suites -- Case Study: Automatic test case generation for a secure cache Implementation -- Verifying Code Generation Tools for the B-Method Using Tests: a Case Study -- Software Validation via Model Animation -- Sequential generation of structured arrays and its deductive verification -- Checking UML and OCL Model Consistency: An Experience Report on a Middle-Sized Case Study -- A constraint optimization model for analysis of telecommunication protocol logs -- Experimental Evaluation of a Novel Equivalence Class Partition Testing Strategy -- Testing Functional Requirements in UML Activity Diagrams -- Coverage of OCL Operation Specifications and Invariants.

This book constitutes the refereed proceedings of the 9th International Conference on Tests and Proofs, TAP 2015, held in L` Aquila, Italy, in July 2015, as part of the STAF 2015 Federated Conferences. The 11 revised full papers and 1 short papers presented together with 3 invited talks were carefully reviewed and selected from 21 submissions. The accepted papers contribute to various testing techniques (model-based, property-based, grammar-based, bounded-exhaustive), fault localization, model-driven engineering, as well as model coverage, consistency and validation, among others. Many papers rely on interactive and automatic theorem provers, including SMT solvers and model checkers.