We introduce nominal string diagrams as string diagrams internal in the category of nominal sets. This leads us to define nominal PROPs and nominal monoidal theories. We show that the categories of ordinary PROPs and nominal PROPs are equivalent. This equivalence is then extended to symmetric monoidal theories and nominal monoidal theories, which allows us to transfer completeness results between ordinary and nominal calculi for string diagrams.

@article{paperbot2242,
  title = {Completeness of Nominal PROPs},
  author = {Samuel Balco and Alexander Kurz},
  journal = {Logical Methods in Computer Science},
  volume = {Volume 19, Issue 1},
  year = {2023},
  doi = {10.46298/lmcs-19(1:8)2023}
}