Eerke Boiten spent the first twenty years of his research career, first in the Netherlands and then in the UK, on mathematics and logic based methods to guarantee and verify the correctness of software. He published over 50 peer reviewed papers on formal methods, including program transformation, viewpoint specification, and refinement in process algebra and state-based systems (e.g. Z). On the latter topic, he authored the monographs “Refinement in Z and Object-Z” (Springer 2004, 2015) and "Refinement: Semantics, Languages and Applications" (Springer 2018) with John Derrick , and organised many conferences and workshops including nine editions of the BCS-FACS Refinement Workshop.