  This article describes an evaluation of Automated Theorem Proving (ATP)
systems on problems taken from the QMLTP library of first-order modal logic
problems. Principally, the problems are translated to both typed first-order
and higher-order logic in the TPTP language using an embedding approach, and
solved using first-order resp. higher-order logic ATP systems and model
finders. Additionally, the results from native modal logic ATP systems are
considered, and compared with the results from the embedding approach. The
findings are that the embedding process is reliable and successful when
state-of-the-art ATP systems are used as backend reasoners, The first-order and
higher-order embeddings perform similarly, native modal logic ATP systems have
comparable performance to classical systems using the embedding for proving
theorems, native modal logic ATP systems are outperformed by the embedding
approach for disproving conjectures, and the embedding approach can cope with a
wider range of modal logics than the native modal systems considered.
