Relational verification through dynamic logic is a promising approach for verifying object oriented programs. Recent advances from symbolic to abstract executions have enabled reasoning about incomplete/abstract versions of such programs. This has proven fruitful in the exploration of correctness of refactorings primarily related to code blocks in Java. In this paper we explore further types of equivalent transformations and refactorings and discuss the challenges that still need to be overcome for full round-trip correctness of refactorings in object-oriented languages.

In the originally published version of this chapter a sentence in the 4th paragraph of section 5 "Discussion" was incomplete. This has been corrected and the sentence has been updated as follows "Conversely, due to the challenges in checking instantiation of schemata against concrete programs already pointed out by Steinhöfel [28, 119,137], one has to take care not to write too restrictive programs that rule out useful working instances.