A verified output is its coordinate.

Twelve worked examples. Same seven axes. Each artifact’s coordinate is the tuple of its measured values. Position predicts behavior — what produced the step, what oracle checked it, what cache it drew from, what it cost in joules.

c = ⟨ S, V, E, D, C, R, τ ⟩

Lean: omega closes a linear-arithmetic goal

KERNEL AUTOMATION · CPU

S₁ · V₁ · E₁ · D₁ · C₁ · R₁ · τ₂

A goal in Presburger arithmetic — sums, differences, linear inequalities over integers — closes in a single tactic line. CPU-bound, sub-millisecond, no GPU. Most subgoals in real proofs look like this and never need anything more.

Lean: aesop hammer over Mathlib

KERNEL AUTOMATION · PREMISE SEARCH

S₁ · V₁ · E₂ · D₂ · C₂ · R₁ · τ₂

Best-first proof search bounded by depth, drawing premises from Mathlib. Discharges a wide class of routine algebraic and order-theoretic goals. The lemma-warm cache regime makes this the workhorse tier of any real proof effort.

Z3 discharges a bit-vector equality

DECISION PROCEDURE · SMT

S₂ · V₂ · E₂ · D₂ · C₁ · R₁ · τ₂

A goal over bit-vectors of fixed width — typical in cryptographic and hardware verification — falls inside the decidable envelope. The SMT solver returns a proof certificate; the kernel re-checks. Polynomial-to-exponential CPU cost; no GPU.

Kani checks a Rust function

BOUNDED MODEL CHECK · CBMC

S₂ · V₃ · E₂ · D₂ · C₁ · R₁ · τ₂

A Rust function annotated with proof harnesses (preconditions, post-conditions) is checked by Kani via CBMC for bounded depth. Catches panics, overflow, and assertion violations within the bound. Not full functional correctness, but cheap and a real guarantee where it applies.

Rust borrow-checker: no use-after-free

TYPE SYSTEM · COMPILE-TIME

S₁ · V₄ · E₀ · D₁ · C₄ · R₁ · τ₄

Memory safety and data-race freedom for the whole program, proven at compile time by the type system. The "solver" is the type checker, the proof is the type derivation, the artifact is the compiled binary. Distilled into the language itself; no per-program search cost.

Distilled prover: one Olympiad lemma

SMALL MODEL · CONSTRAINED DECODE

S₃ · V₁ · E₃ · D₃ · C₂ · R₃ · τ₂

A 1–7B in-domain model proposes tactics under grammar constraints; the kernel applies and checks. Stochastic-bounded (pass@k > 1). The order-of-magnitude inflection over decision procedures starts here, but so does the energy bill.

Open-weight prover: Putnam-grade closure

OPEN-WEIGHT · TREE SEARCH

S₄ · V₁ · E₄ · D₄ · C₂ · R₃ · τ₃

DeepSeek-Prover, Goedel-Prover, Kimina, Numina-Lean-Agent, Leanstral and similar open-weight provers, used as the search backend. Whole-proof draft with kernel-fed feedback. Indexed into a cross-project proof DB; verifiable, replicable across runs at fixed seed.

AlphaProof-style RL inside Lean

HYBRID · MCTS + LEAN

S₅ · V₁ · E₅ · D₄ · C₁ · R₃ · τ₃

AlphaZero-style reinforcement learning with the Lean kernel as the reward oracle. Reported as several hundred TPU-days per Olympiad-class problem in 2024; cost has since fallen roughly an order of magnitude. The current upper bound on autonomous search energy.

CompCert: a verified C compilation

INTERACTIVE PROOF · COQ

S₁ · V₁ · E₂ · D₃ · C₄ · R₁ · τ₄

CompCert's correctness proof in Coq, library-integrated and re-checked on every release. The amortization is total: the proof was written once, the artifact ships with every certified compilation. Used in safety-critical avionics.

seL4: a verified microkernel

INTERACTIVE PROOF · ISABELLE/HOL

S₁ · V₁ · E₂ · D₃ · C₄ · R₁ · τ₄

Functional correctness, security, and refinement proofs for a complete OS microkernel in Isabelle/HOL. Roughly twenty person-years for under ten thousand lines of C — the canonical example of why automation matters, and why the joules question is downstream of the proof-labor question.

HACL* / EverCrypt verified primitives

INTERACTIVE PROOF · F⋆

S₁ · V₁ · E₂ · D₃ · C₄ · R₁ · τ₄

Verified cryptographic primitives in F⋆, library-integrated into Firefox, the Linux kernel, and other production systems. The deepest demonstration that "the spec exists" is the binding constraint — for crypto it does, and the verified artifact ships.

Mathlib lemma promoted from a proof attempt

LIBRARY INTEGRATION · MATHLIB

S₃ · V₁ · E₃ · D₃ · C₂ · R₁ · τ₄

A useful lemma surfaced during one project's proof attempt, refactored and promoted into Mathlib. From that point forward every Lean user can call it via premise selection; the energy paid to produce it amortizes across every future cold proof in the ecosystem.

Two artifacts with nothing in common can sit at adjacent coordinates — a Z3 bit-vector discharge and a Kani Rust check share most of their tuple. Two with the same name (different solver tiers) sit twelve orders apart on E. The stack is what the difference looks like.

From the table to the ladder.