  Refinement is one of the cornerstones of a formal approach to software
engineering. Refinement is the process of developing a more detailed design or
implementation from an abstract specification through a sequence of
mathematically-based steps that maintain correctness with respect to the
original specification. Work on the foundations of languages such as Z, B, VDM
and CSP have led to their widespread use in certain industrial sectors, e.g.,
those with security or safety critical concerns. In addition to precise
specification, formal methods also allow the possibility of precise and
verifiable development, as captured by the concept of refinement.
  The 18th Refinement Workshop was held as part of FLoC 2018 at Oxford, UK.
