nLab nLab formalization index

This page provides an index of machine-checked formalizations of mathematical constructions documented on the nLab.

The index is organized by mathematical subject rather than by proof assistant. Formal verification and human semantic review are recorded separately.

Contents

Formalizations

Homotopy theory
Paths and identity types

Homogeneous path type (FI-001)

nLab: identity type
Cubical Agda: Cubical.Core.Primitives.Path
Scope: Homogeneous path type Path A a b.
Source: Pinned Agda source

Classification: plausible structural correspondence.
Machine verification: source verified; not independently rebuilt.
Human semantic review: pending.

Dependent path type (FI-002)

nLab: identity type
Cubical Agda: Cubical.Core.Primitives.PathP
Scope: Dependent paths in a family over the cubical interval.
Source: Pinned Agda source

Classification: partial correspondence; the nLab discussion is broader than the primitive presentation.
Machine verification: source verified; primitive not independently rebuilt.
Human semantic review: pending.

Path composition (FI-003)

nLab: equality in type theory (Typal equality, Transitivity)
Cubical Agda: Cubical.Foundations.Prelude._∙_
Scope: Composition of paths, first p, then q.
Source: Pinned Agda source

Classification: plausible structural correspondence.
Machine verification: source verified; not independently rebuilt.
Human semantic review: pending.

Identity-system characterization (FI-004)

nLab: equality in type theory
1Lab: 1Lab.Path.IdentitySystem.identity-system-gives-path
Scope: An identity-system witness yields an equivalence R a b ≃ (a ≡ b).
Source: Official documentation (revision d45acb1d16acb2472ade6f1cfbad4ba00867ad1c)

Classification: partial correspondence; not the same construction as path inversion.
Machine verification: source verified; no 1Lab build reproduced.
Human semantic review: pending.

Dependent total spaces, homotopy fibers, and pullbacks

Dependent total space (FI-005)

nLab: dependent type
Cubical Agda: Cubical.Core.Primitives.Σ (re-exported by Cubical.Data.Sigma)
Scope: Dependent sums of type families.
Source: Pinned Agda source

Correspondence evidence: Both constructions represent dependent sums. This does not imply a classical lifting-property fibration.
Machine verification: source verified; primitive not independently rebuilt.
Human semantic review: pending.

Homotopy fiber of a map (FI-006)

nLab: homotopy fiber
Cubical Agda: Cubical.Foundations.Equiv.Base.fiber
Scope: Homotopy fiber of a map f : A → B over a point y : B.
Source: Pinned Agda source

Correspondence evidence: The Agda declaration defines the fiber using dependent pairs and paths to the specified point.
Machine verification: source verified; not independently rebuilt.
Human semantic review: pending.

Fiber of a dependent total-space projection (FI-007)

nLab: homotopy pullback
Cubical Agda: NLabMonodromy.total-hofib≃
Scope: The equivalence fiber (total-projection P) b ≃ P b.
Source: Verified Agda implementation

Correspondence evidence: The formal declaration establishes the homotopy-fiber equivalence for the projection of a dependent total space; this is a specific instance related to the homotopy-pullback construction, not a formalization of every homotopy pullback.
Machine verification: independently type-checked by the pilot.
Human semantic review: pending.

Monodromy — Cubical Agda

The construction of monodromy in homotopy type theory can be expressed through transport along paths in dependent type families.

Formalization: Transport equivalences, loop-space monodromy, pointed transport, and induced equivalences on higher homotopy groups.

Verification: Agda 2.8.0, Cubical Library v0.9 — type-checked.

Human mathematical and semantic review: Pending.

Scope limitation: The complete fundamental-group action on fixed-basepoint higher homotopy groups has not yet been formalized.

Last revised on November 9, 2026 at 19:43:13. See the history of this page for a list of all contributions to it.