@article{zippy,
  doi = {10.48550/ARXIV.2503.20413},
  author = {Kappelmann, Kevin},
  note = {Work In Progress},
  title = {{Zippy -- Generic White-Box Proof Search with Zippers}},
  year = {2025}
}

@article{ML_Unification-AFP,
  author  = {Kevin Kappelmann},
  title   = {{Unification Utilities for Isabelle/ML}},
  journal = {Archive of Formal Proofs},
  month   = {September},
  year    = {2023},
  note    = {\url{https://isa-afp.org/entries/ML_Unification.html},
             Formal proof development},
  ISSN    = {2150-914x},
}