Dependently typing JVM method invocation

Code certi cation is a promising technique that supports secure and e cient applications on the internet. Annotating code with index types allows strong program properties to be asserted and checked. In this paper, we report our experience of applying a restricted form of dependent types to JVMLi, a subset of Java Virtual Machine Language (JVML). The result is a type system for JVMLi that can guarantee safe elimination of some of the array bound checks. We show how our restriction on the type terms results in a clean coding of method invocation in this rst-order language with explicit control. We also discuss the trade-o between expressive power and decidability, which is a key issue of the type system for code certi cation. In addition, we describe our implementation of the type system.