Effectiveness of Annotation-Based Static Type Inference

Benefits of static type systems are well-known: they offer guarantees that no error will occur during runtime and, inherently, inferred types serve as documentation on how functions called. On the other hand, many have to limit expressiveness language because, in general, it is undecidable whether a given program correct regarding types. Another concern was not addressed so far that, for logic programming languages such Prolog, impossible distinguish between intended and unintended failure worse, success without additional annotations.