Files
proofs/lean/Protocol/Nebula.lean
zooqueenandHanzo Dev d3bff5e2dc proofs: drive Lean library to 0 errors, eliminate proof-by-assumption axioms
The lean/ proof library (88 files) had ~180 type-check errors across ~45 files
plus 31 proof-by-assumption axiom cheats. It now type-checks cleanly under
Lean 4.14.0 + Mathlib, with every theorem genuinely proven from definitions.

Errors fixed:
- Stale Mathlib imports: Data.Nat.Basic / Data.Int.Basic were removed this rev
  -> Data.Nat.Defs / Data.Int.Defs (57 files).
- Shared AI/Agent/Governance/Contract/DeFi/Ecology draft files: same proof-rot
  as the zoo-labs sibling library (now reconciled): omega missing in-scope
  bounds, dead tactics after simp, simp over-reduction, doc-comment placement,
  reserved-word binders, deriving Repr on Finset-bearing structs, noncomputable
  defs over opaque primitives.
- Consensus/Liveness: collapsed a 74-error cascade (undefined shared state model
  inlined from Safety.lean; the |>. pipe-projection vs comparison parse trap on
  14 lines rewritten to explicit dot projection).
- Crypto (BLS/FROST/Corona/Hybrid/threshold/FHE), Consensus, Protocol, Warp,
  Trust, GPU, Compute, Network, DeFi: brought structure invariants into scope
  for omega, Nat-division bounds via Nat.div_le_of_le_mul / Nat.div_mul_le_self,
  noncomputable over opaque crypto ops, deriving Inhabited for index access.

Integrity:
- Removed all 31 `theorem X := X_ax` cheats (axiom asserting the identical
  statement) and proved each from definitions; removed the UNSOUND
  content_addressed axiom (hash-injectivity over a struct with free fields).
- Quorum-intersection theorems (BFT/Quasar/Flare/Warp/BLS/GPU/Bridge): the draft
  hypothesis 3f<n is insufficient (n unbounded above makes them false); tightened
  to the optimal-resilience invariant n=3f+1 / 2t>n. Statement intent preserved.
- Net axiom change: -35 / +1 (the one addition, honesty_static, is a
  fixed-validator-set modeling assumption matching sibling files).
- Remaining axioms are trusted-base only: opaque crypto primitives (groups,
  pairings, hardness, hashes, FHE encrypt/decrypt, BLS soundness, forward
  secrecy, Fisher-Yates uniformity) and protocol modeling assumptions. No
  sorry/admit/native_decide. Verified all theorems trace to
  [propext, Classical.choice, Quot.sound] plus those primitives.

Co-authored-by: Hanzo Dev <[email protected]>
2026-06-02 05:54:28 -07:00

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/-
Authors: Antje Worring, Zach Kelling
Nebula Protocol Formal Model
Models protocol/nebula/nebula.go -- DAG consensus mode.
Nebula wraps Field (DAG decision engine) and provides DAG blockchain semantics.
Composition: Nebula -> Field -> Wave -> Prism (sampling)
-> Flare (cert/skip)
Maps to:
- nebula.go: Nebula struct wrapping field.Driver
- nebula.go: Config{PollSize, Alpha, Beta, RoundTO, GenesisSet}
Properties:
- DAG validity: all parent references resolve to existing vertices
- Consistent ordering: committed vertices respect topological order
- Nebula delegates invariants to Field (consistent cut property)
-/
import Mathlib.Data.Nat.Defs
import Mathlib.Data.Finset.Basic
import Mathlib.Tactic
namespace Protocol.Nebula
/- Nebula is a thin wrapper around Field. Its correctness reduces to Field's. -/
/-- A DAG vertex -/
structure Vertex where
id : Nat
parents : List Nat
round : Nat
author : Nat
/-- Nebula state -/
structure NebulaState where
vertices : Finset Nat -- all known vertex IDs
committed : Finset Nat -- committed vertex IDs
round : Nat -- current round
/-- Topological order: if u is parent of v, u appears before v in ordering -/
def IsTopologicalOrder (vertices : List Vertex) : Prop :=
∀ i j : Fin vertices.length,
(vertices[i]).id ∈ (vertices[j]).parents →
i.val < j.val
/-- Committed set only grows -/
theorem committed_monotone (s : NebulaState) (newCommits : Finset Nat) :
s.committed ⊆ s.committed ∪ newCommits :=
Finset.subset_union_left
/-- Vertices only increase -/
theorem vertices_monotone (s : NebulaState) (newVerts : Finset Nat) :
s.vertices ⊆ s.vertices ∪ newVerts :=
Finset.subset_union_left
/-- Committed is subset of vertices -/
def validState (s : NebulaState) : Prop :=
s.committed ⊆ s.vertices
/-- Round advances monotonically -/
theorem round_monotone (s : NebulaState) (newRound : Nat) (h : newRound ≥ s.round) :
newRound ≥ s.round := h
end Protocol.Nebula