FC07 — Hatcher, Algebraic Topology

This book contains 137 definitions, 71 theorems, 116 propositions, 27 lemmas, 47 corollaries, 152 examples, 54 constructions, 5 conventions and 3 other statements.

612 of its 612 statements have been checked against Lean; 102 of those are formalized somewhere.

Chapter Definitions Theorems, propositions Lemmas, corollaries Everything else Formalized Not formalized
Chapter 0. Some Underlying Geometric Notions 10 4 2 25 11 30
Chapter 1. The Fundamental Group 21 30 7 36 44 50
Chapter 2. Homology 25 29 11 33 20 78
Chapter 3. Cohomology 34 42 19 64 12 147
Chapter 4. Homotopy Theory 38 67 31 52 5 183
Appendix. Topology of Cell Complexes 9 15 4 4 10 22

What the book contains

Kind of statement Count
Definitions 137
Theorems 71
Propositions 116
Lemmas 27
Corollaries 47
Examples 152
Constructions 54
Conventions 5
Other statements 3
Total 612

Where its statements stand in Lean

Status Statements Share What it means
not formalized 510 83% A documented search found no Lean statement of it anywhere.
in Mathlib 82 13% Mathlib states and proves it.
in another Lean project 20 3% Some other Lean development has it; using it means porting that code.
checked in total 612

How this book was read

Corpus source: FC07 in Foundational source corpus v1 (frozen).

This is the canonical Sweep-I source-unit catalogue for FC07. Stable source-local IDs are consumed unchanged by Sweeps II–IV.

Frozen source: Hatcher - 2002 - Algebraic Topology.md

Scope: complete book, Chapters 0–4 and Appendix; exercises excluded item-by-item. Stable IDs are chapter-local and source-ordered; dependencies point only to strictly earlier FC07 units.