We propose a framework to study contextual equivalence of programs written in a call-by-value functional language with local integer references. It reduces the problem of contextual equivalence to the problem of non-reachability in a transition system of memory configurations. This reduction is complete for recursion-free programs. Restricting to programs that do not allocate references inside the body of functions, we encode this non-reachability problem as a set of constrained Horn clause that can then be checked for satisfiability automatically. Restricting furthermore to a language with finite data-types, we also get a new decidability result for contextual equivalence at any type.

@article{paperbot514,
  title = {SyTeCi: automating contextual equivalence for higher-order programs with references},
  author = {Guilhem Jaber},
  journal = {Proceedings of the ACM on Programming Languages},
  volume = {4},
  number = {POPL},
  year = {2019},
  doi = {10.1145/3371127}
}