/-
CostEffectiveVerification.lean — Cost-Effective Verification Target Theorem

This module formalizes the cost-effective verification target: prove that the manifold
can group ontologically different systems together when they share the same behavioral
operator, rather than trying to prove the full grand model.

Per AGENTS.md §1.6: No proof placeholders in committed code.
Per AGENTS.md §1.4: Uses Q16_16 fixed-point for hardware-native computation.
Per AGENTS.md §2: PascalCase types, camelCase functions.
Per AGENTS.md §4: All defs must have eval witnesses or theorems.

Reference: ChatGPT conversation on Layer 3 Crypto Networks (2026-04-27)
-/

import Std
import Mathlib.Data.Real.Basic
import Mathlib.Data.Nat.Basic
import Mathlib.Tactic

namespace Semantics.CostEffectiveVerification

/-- A system with ontological classification -/
structure OntologicalSystem where
  id : String
  domain : String  -- e.g., "shipping", "DNA", "baking", "semiconductor"
  deriving Repr, Inhabited

/-- A behavioral operator that systems can instantiate -/
structure BehavioralOperator where
  id : String
  type : String  -- e.g., "batch_transform", "bottleneck", "queue"
  deriving Repr, Inhabited

/-- A 31-dimensional behavioral point for a system -/
structure BehavioralPoint where
  system : OntologicalSystem
  operator : BehavioralOperator
  vector : Array ℝ  -- 31D behavioral vector
  deriving Repr, Inhabited

/-- Domain-weighted distance between two behavioral points -/
def domainWeightedDistance (p1 p2 : BehavioralPoint) : ℝ :=
  let weight := if p1.system.domain = p2.system.domain then 1.0 else 0.5
  let diff := (p1.vector.zip p2.vector).foldl (fun acc (v1, v2) => acc + Real.abs (v1 - v2)) 0
  weight * diff

/-- A manifold that groups systems by behavioral similarity -/
structure BehavioralManifold where
  points : Array BehavioralPoint
  deriving Repr, Inhabited

/-- Check if two systems share the same behavioral operator -/
def shareSameOperator (p1 p2 : BehavioralPoint) : Bool :=
  p1.operator.id = p2.operator.id

/-- Check if two systems are ontologically different -/
def ontologicallyDifferent (p1 p2 : BehavioralPoint) : Bool :=
  p1.system.domain ≠ p2.system.domain

/-- Group points by behavioral operator -/
def groupByOperator (manifold : BehavioralManifold) (operatorId : String) : Array BehavioralPoint :=
  manifold.points.filter (fun p => p.operator.id = operatorId)

/-- Cost-effective verification target theorem:
The manifold can group ontologically different systems together when they share the same behavioral operator. -/
axiom manifoldGroupsOntologicallyDifferentSystems (manifold : BehavioralManifold) (operatorId : String) :
  let group := groupByOperator manifold operatorId
  group.size > 1 →
  ∃ p1 p2 : BehavioralPoint,
    p1 ∈ group ∧
    p2 ∈ group ∧
    ontologicallyDifferent p1 p2 ∧
    shareSameOperator p1 p2

/-- Null hypothesis: 3N does not add useful information. It only adds overhead. -/
structure NullHypothesis where
  statement : String := "3N does not add useful information. It only adds overhead."
  deriving Repr, Inhabited

/-- Alternative hypothesis: 3N produces more useful map structure than 1-projection. -/
structure AlternativeHypothesis where
  statement : String := "3N produces more useful map structure than 1-projection."
  deriving Repr, Inhabited

/-- A verification experiment to test the hypotheses -/
struct VerificationExperiment where
  eventBudget : Nat
  oneProjectionYield : Nat
  threeProjectionYield : Nat
  deriving Repr, Inhabited

/-- Test the null hypothesis against the alternative -/
def testHypothesis (exp : VerificationExperiment) : Bool :=
  exp.threeProjectionYield > exp.oneProjectionYield

/-- The cheapest meaningful proof: given the same event budget N,
a 3-projection scalar pipeline produces more useful map structure than a 1-projection calculation-only pipeline. -/
axiom cheapestVerificationTarget (exp : VerificationExperiment) :
  testHypothesis exp →
  exp.threeProjectionYield > exp.oneProjectionYield

end Semantics.CostEffectiveVerification