Abstract. Recently, we developed an approach for automated termination proofs of Java Bytecode (JBC), which is based on constructing and analyzing termination graphs. These graphs represent all possible program executions in a finite way. In this paper, we show that this approach can also be used to detect non-termination or NullPointerExceptions. Our approach automatically generates witnesses, i.e., calling the program with these witness arguments indeed leads to non-termination resp. to a NullPointerException. Thus, we never obtain “false positives”. We implemented our results in the termination prover AProVE and provide experimental evidence for the power of our approach. 1

Abstract. Partial evaluation is a program specialization technique that allows to optimize a program for which partial input is known. We propose a new approach to generate specialized programs for a Java-like language via the software verification tool KeY. This is achieved by symbolically executing source programs interleaved with calls to a simple partial evaluator. In a second phase the specialized programs are synthesized from the symbolic execution tree. The correctness of this approach is guaranteed by a bisimulation relation on the source and specialized programs.

Abstract. Recently, we developed an approach for automated termination proofs of Java Bytecode (JBC), which is based on constructing and analyzing termination graphs. These graphs represent all possible program executions in afiniteway. Inthis paper, we showthat this approach can also be used to detect non-termination or NullPointerExceptions. Ourapproach automatically generates witnesses, i.e., calling theprogram with these witness arguments indeed leads to non-termination resp. to a NullPointerException. Thus, we never obtain “false positives”. We implemented our results in the termination prover AProVE and provide experimental evidence for the power of our approach. 1