English

Internal languages of locally cartesian closed $(\infty,1)$-categories

Category Theory 2026-03-03 v2 Algebraic Topology Logic

Abstract

We establish a DK-equivalence between the relative category of π\pi-tribes and the relative category of locally cartesian closed quasicategories. From this follows one of the internal languages conjecture: Martin-L\"of type theory with dependent sums, intensional identity types, and dependent products satisfying functional extensionality is the internal language of locally cartesian closed (,1)(\infty,1)-categories.

Cite

@article{arxiv.2509.03371,
  title  = {Internal languages of locally cartesian closed $(\infty,1)$-categories},
  author = {El Mehdi Cherradi},
  journal= {arXiv preprint arXiv:2509.03371},
  year   = {2026}
}

Comments

v2; 41 pages, includes several corrections and information refactoring: parts of v1 have been made independent and expanded on separately (arXiv:2602.17347 and arXiv:2602.21083)

R2 v1 2026-07-01T05:19:22.636Z