Comparison of Proof Assistants for the Physics Derivation Graph

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Recommendation: Read the user documentation and FAQ first. This page assumes familiarity with the jargon used in the Physics Derivation Graph.

What constitutes a viable proof assistant option? Cited by a journal like Annals of Formalized Mathematics,

"Examples of popular proof assistants include Agda, Rocq, HOL Light, Isabelle, Lean, and Mizar."
Aspect Agda Rocq HOL Light Isabelle Lean Mizar
wikipedia page Agda Rocq HOL Light Isabelle Lean Mizar
Primary Community Computer scientists, Programming Language (PL) researchers, HoTT theorists. Large mix of industry (software verification) and academic mathematicians. Hardware verification specialists and extreme minimalists. Computer science departments and formal methods researchers. Working research mathematicians and "Mathlib" contributors. Traditional mathematicians focused on a human-readable library.
Foundational Logic Dependent Type Theory (DTT) / Constructive. Calculus of Inductive Constructions (CIC). Higher-Order Logic (Simple Type Theory). Higher-Order Logic (built on a meta-logic). Dependent Type Theory (similar to Rocq). Tarski-Grothendieck Set Theory.
Strengths Beautiful syntax; "Programs are Proofs"; excellent for Homotopy Type Theory. Powerful tactic engine; highly stable; massive industry track record (e.g., CompCert). Extremely small, trustworthy kernel; very fast execution of simple proofs. "Sledgehammer" (powerful automation); very readable proof scripts (Isar syntax). Unified, massive math library (mathlib); excellent VS Code integration; fast-growing. Human-readable language style; the oldest continuous math library (MML).
Weaknesses Lacks the heavy automation/tactics found in Isabelle or Rocq. Steep learning curve; legacy fragmentation across 30 years of development. Sparse user interface; requires OCaml proficiency; less automated than Isabelle. The "Logic of Choice" (HOL) is not constructive; heavy resource usage. Rapid version changes (transitioning to Lean 4 was difficult); heavy RAM requirements. Hard to extend; lacks modern IDE features; rigid structure for new users.
Math Coverage Strong in Category Theory, Type Theory, and Logic. Broad coverage; famous for Feit-Thompson (Group Theory) and Four Color Theorem. Very deep in Analysis and Geometry (famous for the Flyspeck Project). Massive "Archive of Formal Proofs" (AFP) covering diverse undergraduate/graduate math. Modern research math (Perfectoid spaces, Liquid Tensor Experiment, Algebra). Extensive library (MML) covering a wide range of classical mathematics.
Automation Style Mostly manual/structural; relies on "interactive editing" via Emacs. Ltac tactic language allows users to write custom automation scripts. Manual tactic application via OCaml prompts. Excellent: Sledgehammer connects to external solvers (Z3, Vampire, E). Strong: "Aesop" and "Tactic" frameworks; growing AI/LLM integration. The "Checker" automatically fills in "obvious" gaps between steps.
Library Philosophy Decentralized; standard library is separate from specialized research. Decentralized; many independent packages managed via Opam. Monolithic: Centered around a core set of files used by the community. The AFP (Archive of Formal Proofs) acts as a curated journal for libraries. Hyper-centralized: One giant repository (mathlib) that keeps everything in sync. Monolithic: The Mizar Mathematical Library (MML) is a single, integrated body.

Prompt to Gemini 3 Flash on 2026-03-05:

Create an HTML table that has, as columns, Agda, Rocq, HOL Light, Isabelle, Lean, and Mizar.
The rows should have aspects that compare the proof assistants. Example comparisons might include
- which communities is the proof assistant popular with?
- strengths and weaknesses
- what aspects of math are covered?

Come up with additional rows for comparison and fill in the table with an assessment.

HOL

HOL Light theorem prover

HOL Light tutorial

https://hub.docker.com/r/lcdoutlet/hol-light/

An attempted Docker image: https://github.com/allofphysicsgraph/proofofconcept/blob/gh-pages/sandbox/docker_images/ocaml_alipne_with_hol_works/Dockerfile
and https://github.com/allofphysicsgraph/proofofconcept/blob/gh-pages/sandbox/docker_images/ocaml_alpine_with_HOL/Dockerfile