Release date: April 19, 2026 (peer-review-fixes-v1 merged; ci-python-sorry-checker merged) Previous release: v1.0.0 (April 12, 2026; see CHANGELOG.md) Lean version: 4.28.0-rc1 License: Apache 2.0
TauLib is a 126,000-line Lean 4 formalization of Category tau -- a categorical framework built from 7 axioms (K0-K6) on 5 generators with a single primitive iterator. Starting from these axioms alone, TauLib derives arithmetic, analysis, geometry, physics, biology, and philosophy as earned consequences -- all compiled and verified by Lean's kernel.
Companion to the 7-book Panta Rhei series by Thorsten Fuchs and Anna-Sophie Fuchs (2nd Edition, 2026). Published at panta-rhei.site.
| Metric | Value |
|---|---|
| Modules | 450 |
| Lines of Lean 4 | 125,771 |
| Theorems | 4,332 |
| Definitions | 3,542 |
| Live computations | 3,721 |
| Axioms | 3 |
| Sorry | 0 |
TauLib imports no mathematical content from Mathlib or any other library. Arithmetic, algebra, analysis, topology, category theory, quantum mechanics, and cosmology are all derived within the framework from 5 generators and 7 axioms. Mathlib is used for proof tactics only.
The master constant iota_tau = 2/(pi + e) generates predictions for the fine-structure constant, CMB first peak position (+69 ppm), Hubble parameter, baryon density, tensor-to-scalar ratio, and galaxy rotation curves -- all without fitting.
The 3 axioms (all conjectural, all Book III) and 0 sorry are explicitly documented with precise classification. The 3 conjectural axioms follow a compute-then-axiomatize pattern: finite checks pass computationally; the axiom asserts the infinite extension. The three Book VII structural commitments are encoded as def values of a Commitment structure (see BookVII/Meta/Commitment.lean), not as sorry — all seven books are sorry-free. Note: v2 shipped with 4 axioms and 3 sorry until peer-review-fixes-v1 merged on 2026-04-19 (commit a2d3384).
Interactive step-through tours for mathematicians, physicists, biologists, philosophers, skeptics, and Lean users. Open any tour in VS Code and evaluate line by line.
| Axiom | Location | Type | Finite check |
|---|---|---|---|
bridge_functor_exists |
BookIII/Bridge | Conjectural | bridge_functor_check |
grand_grh_adelic |
BookIII/Doors | Conjectural | grand_grh_finite_check |
spectral_correspondence_O3 |
BookIII/Doors | Conjectural | spectral_correspondence_finite |
Retired in peer-review-fixes-v1 (2026-04-19): a fourth axiom central_theorem_physical : True in BookIV/Arena/BoundaryHolonomy. An axiom of type True is a no-op (True is inhabited by trivial); pre-publication simulated peer review identified it as a null commitment inflating the axiom count. The architectural intent survives as a documentation pointer from Book IV to Book II's central_theorem_check.
All seven books of TauLib are now sorry-free. Books I–VI have been sorry-free since Wave 12; the three previously shipping Book VII theorem X : True := sorry declarations (omega_point_theorem, science_faith_boundary, no_forced_stance) were retired in peer-review-fixes-v1 (2026-04-19) and replaced with def values of a Commitment structure in BookVII/Meta/Commitment.lean. Each def carries the commitment's statement, warrant, and registry_id as inspectable String data — readable via #eval — rather than as an unprovable sorry on a trivially-provable True goal.
This release targets Lean 4.28.0-rc1 (release candidate). Build compatibility with future Lean versions is not guaranteed but expected to be straightforward.
# Install Lean 4 via elan (if not already installed)
curl https://raw.githubusercontent.com/leanprover/elan/master/elan-init.sh -sSf | sh
# Clone and build
git clone https://github.com/Panta-Rhei-Research/taulib.git
cd taulib
lake buildFirst build downloads Mathlib (for tactics) and compiles ~1,256 lake jobs.
@software{taulib2026,
author = {Fuchs, Thorsten and Fuchs, Anna-Sophie},
title = {{TauLib}: Mechanized Formalization of Category $\tau$},
year = {2026},
version = {1.0.0},
url = {https://github.com/panta-rhei-research/taulib},
note = {450 modules, 125,771 lines of Lean 4, 4,332 theorems},
license = {Apache-2.0}
}This release has undergone three comprehensive audits:
- Cross-Reference Audit: All 545 chapters x 445 modules x 4,547 registry entries verified
- Content Audit: 220 audit units checked for bidirectional consistency
- Codebase Audit: 745 documentation fixes applied across 235 files
Audit reports are available in the audits/ directory.