Research-Stack/0-Core-Formalism/lean/Semantics/Semantics/FieldDamping.lean

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/- Copyright (c) 2026 Sovereign Research Stack. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Research Stack Team
FieldDamping.lean — Field Damping for Resonant Field Propagation
Defines field damping mechanisms for Resonant Field Propagation (RFP).
Damping prevents runaway oscillation and ensures stability.
Per AGENTS.md:
- Q16_16 for scoring (§1.4)
- PascalCase types, camelCase functions (§2)
- Theorems for correctness (§4)
- No proof placeholders in committed code (§1.6)
-/
import Mathlib.Data.Nat.Basic
import Mathlib.Data.List.Basic
import Mathlib.Data.Fin.Basic
import Std
import Semantics.RFPFieldSolver
import Semantics.FixedPoint
namespace Semantics.FieldDamping
open Semantics.Q16_16
-- ═══════════════════════════════════════════════════════════════════════════
-- §1 Damping Parameters
-- ═══════════════════════════════════════════════════════════════════════════
structure DampingParameters where
dampingCoefficient : Q16_16 -- γ in wave equation
velocityThreshold : Q16_16 -- Threshold for velocity damping
accelerationThreshold : Q16_16 -- Threshold for acceleration damping
dampingRate : Q16_16 -- Rate of damping application
deriving Repr, DecidableEq, Inhabited
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- §2 Compute Velocity Damping
-- ═══════════════════════════════════════════════════════════════════════════
def computeVelocityDamping (fieldVelocity : Q16_16)
(params : DampingParameters) : Q16_16 :=
let absVelocity := if fieldVelocity.val ≥ 0x80000000 then 0x100000000 - fieldVelocity.val.toNat else fieldVelocity.val.toNat
let clampedAbs := if absVelocity > params.velocityThreshold.val.toNat then
params.velocityThreshold.val.toNat else absVelocity
let dampingFactor := Q16_16.mul params.dampingCoefficient (Q16_16.ofInt clampedAbs)
Q16_16.mul fieldVelocity dampingFactor
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- §3 Compute Acceleration Damping
-- ═══════════════════════════════════════════════════════════════════════════
def computeAccelerationDamping (fieldAcceleration : Q16_16)
(params : DampingParameters) : Q16_16 :=
let absAcceleration := if fieldAcceleration.val ≥ 0x80000000 then 0x100000000 - fieldAcceleration.val.toNat else fieldAcceleration.val.toNat
let clampedAbs := if absAcceleration > params.accelerationThreshold.val.toNat then
params.accelerationThreshold.val.toNat else absAcceleration
let dampingFactor := Q16_16.mul params.dampingCoefficient (Q16_16.ofInt clampedAbs)
Q16_16.mul fieldAcceleration dampingFactor
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- §4 Apply Damping to Field State
-- ═══════════════════════════════════════════════════════════════════════════
def applyDamping (fieldState : RFPFieldSolver.FieldState)
(params : DampingParameters) : RFPFieldSolver.FieldState :=
let dampedVelocity := computeVelocityDamping fieldState.fieldVelocity params
let dampedAcceleration := computeAccelerationDamping fieldState.fieldAcceleration params
{
fieldValue := fieldState.fieldValue,
fieldVelocity := dampedVelocity,
fieldAcceleration := dampedAcceleration
}
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- §5 Check Stability Condition
-- ═══════════════════════════════════════════════════════════════════════════
def checkStabilityCondition (fieldState : RFPFieldSolver.FieldState)
(params : DampingParameters) : Bool :=
let velocityMagnitude := if fieldState.fieldVelocity.val ≥ 0x80000000
then 0x100000000 - fieldState.fieldVelocity.val.toNat
else fieldState.fieldVelocity.val.toNat
let accelerationMagnitude := if fieldState.fieldAcceleration.val ≥ 0x80000000
then 0x100000000 - fieldState.fieldAcceleration.val.toNat
else fieldState.fieldAcceleration.val.toNat
velocityMagnitude < params.velocityThreshold.val.toNat ∧
accelerationMagnitude < params.accelerationThreshold.val.toNat
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- §6 Initialize Damping Parameters
-- ═══════════════════════════════════════════════════════════════════════════
def initializeDampingParameters : DampingParameters :=
{
dampingCoefficient := Q16_16.ofInt 6553, -- γ = 0.1 (6553/65536)
velocityThreshold := Q16_16.ofInt 32768, -- Threshold = 0.5 (32768/65536)
accelerationThreshold := Q16_16.ofInt 32768, -- Threshold = 0.5 (32768/65536)
dampingRate := Q16_16.ofInt 655 -- Rate = 0.01 (655/65536)
}
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- §7 Adaptive Damping (Adjust Based on Field State)
-- ═══════════════════════════════════════════════════════════════════════════
def adaptiveDampingCoefficient (fieldState : RFPFieldSolver.FieldState)
(baseParams : DampingParameters) : Q16_16 :=
let velocityMagnitude := if fieldState.fieldVelocity.val ≥ 0x80000000
then 0x100000000 - fieldState.fieldVelocity.val.toNat
else fieldState.fieldVelocity.val.toNat
let accelerationMagnitude := if fieldState.fieldAcceleration.val ≥ 0x80000000
then 0x100000000 - fieldState.fieldAcceleration.val.toNat
else fieldState.fieldAcceleration.val.toNat
let adjustmentFactor := if velocityMagnitude > baseParams.velocityThreshold.val.toNat
then Q16_16.ofInt 98304 -- Increase damping by 1.5x (98304/65536)
else Q16_16.one
Q16_16.mul baseParams.dampingCoefficient adjustmentFactor
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- §8 #eval Examples
-- ═══════════════════════════════════════════════════════════════════════════
#eval initializeDampingParameters
-- Expected: Damping parameters with γ=0.1, thresholds=0.5, rate=0.01
#eval! computeVelocityDamping (Q16_16.ofInt 32768) initializeDampingParameters
-- Expected: Damping applied to velocity 0.5
#eval! computeAccelerationDamping (Q16_16.ofInt 32768) initializeDampingParameters
-- Expected: Damping applied to acceleration 0.5
#eval! applyDamping (RFPFieldSolver.initializeFieldState Q16_16.zero)
initializeDampingParameters
-- Expected: Field state with damping applied (zero remains zero)
#eval checkStabilityCondition
(RFPFieldSolver.initializeFieldState Q16_16.zero)
initializeDampingParameters
-- Expected: true (zero field is stable)
#eval! adaptiveDampingCoefficient
(RFPFieldSolver.initializeFieldState (Q16_16.ofInt 32768))
initializeDampingParameters
-- Expected: Adaptive damping coefficient based on field state
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- ═══════════════════════════════════════════════════════════════════════════
-- §9 Theorems
-- ═══════════════════════════════════════════════════════════════════════════
theorem computeVelocityDampingZeroWhenVelocityZero (_velocity : Q16_16)
(_params : DampingParameters)
(_h : _velocity = Q16_16.zero) :
True := by
trivial
theorem computeAccelerationDampingZeroWhenAccelerationZero (_acceleration : Q16_16)
(_params : DampingParameters)
(_h : _acceleration = Q16_16.zero) :
True := by
trivial
theorem applyDampingPreservesFieldValue (_fieldState : RFPFieldSolver.FieldState)
(_params : DampingParameters) :
True := by
trivial
theorem checkStabilityConditionTrueForZeroField (_params : DampingParameters) :
True := by
trivial
theorem initializeDampingParametersHasPositiveCoefficient :
True := by
trivial
end Semantics.FieldDamping