paper

A Type and Scope Safe Universe of Syntaxes with Binding: Their Semantics and Proofs — Guillaume Allais, Robert Atkey, James Chapman, Conor McBride & James McKinna (2020; extended version of the ICFP 2018 paper). arXiv:2001.11001 (v2, PDF).

Defines, in Agda, a universe of descriptions of syntaxes with binding, a single well-typed and well-scoped term type over all of them, and generic programs — renaming, substitution, printing, elaboration, normalisation by evaluation — together with generic proofs of their properties (fusion, simulation), written once and instantiated for every syntax.

Sources: the paper, arXiv:2001.11001v2, checked against the arXiv listing. Index: Papers.

Key definitions and results

  • §§2–3: primers on scope- and sort-safe terms and on type- and scope-safe programs
  • §5: a universe of scope-safe, well-sorted syntaxes with binding
  • §6: generic scope-safe programs; renaming and substitution as instances of one semantics
  • §7: a catalogue of generic programs (printing, elaboration, normalisation by evaluation, …)
  • §9: generic proofs about generic programs (simulation and fusion)

Concept notes

Abstract Syntax with Binding

Used in Sophia

Hashing and Identity