In our earlier work we presented a method for formal verification of concurrent Java programs based on Dynamic Logic and symbolic permissions. Embedded within the explicit dynamic frames method realised through JML⁎ specifications, permissions to heap locations and the actual heap location values are tracked separately and require two independent and often overlapping frame specifications. This is in contrast to well established Separation Logic and sibling frameworks, where program frames are inferred from permission annotations that already provide implicit framing information.

In this paper we show how to avoid redundant frame specifications and move towards the implicit framing approach in our method. We strive to keep as much as possible of the existing reasoning framework to preserve the general verification philosophy and implementation of our verification tool, the KeY verifier. We achieve our goal by only a small alteration of the existing proof obligation generation without changing any core part of the underlying logic, in particular, we maintain its closed character. However, even though specifications become more natural and less redundant, the indirect character of the specifications introduces a clear performance penalty for the verification engine.

We then proceed to a brief discussion why, under our minimal approach assumptions, this extension is still not sufficient to translate Separation Logic specifications into our framework. © 2020, Springer Nature Switzerland AG.