This strategy converts the recent cumulative return path into two different visibility graphs and studies their boundary topology across nested windows. It is neither a covariance model nor a frequency decomposition. The market hypothesis is geometric: the newest section of a path can have different exposure to earlier observations above and below the path, and persistent directional exposure across scales may indicate continuation. Graph connectivity, rather than a conventional indicator threshold, is the primary analytical representation.

The model builds a chronological cumulative path from recent completed returns and inspects suffix windows of lengths 24, 48, and 96. Every observation is a vertex. For two vertices a and b, it constructs the straight chord joining their path values. In the upper visibility graph an edge exists only when every intermediate path point lies strictly below that chord. In the lower graph every intermediate point must lie strictly above it. Adjacent vertices are visible in both graphs because there are no intervening points. Strict inequalities use a small tolerance proportional to return RMS so numerical ties do not create unstable long-range edges.

For each graph, the implementation counts the degree of every vertex. It then compares the mean degree of the newest four vertices with the mean degree of the remaining vertices. The local boundary contrast is boundary = (recent_upper - recent_lower)/(recent_upper + recent_lower). The bulk contrast is defined in the same way for older vertices, with denominators floored for numerical safety. Their difference is contrast = boundary - bulk. Contrasts from the three window lengths receive weights 1, 1/2, and 1/3, followed by normalization by the sum of those weights.

The resulting signed graph score is not enough by itself. The average of the most recent twelve returns must point in the same direction. Quality is based on the magnitude of the multiscale connectivity contrasts, and the edge clips twice the weighted graph score to the interval from minus one to one. The shared execution thresholds can reject weak graph evidence. An eligible position has a maximum holding duration of ten hourly bars, but loss of positive exposure or low quality can trigger an earlier exit.

Natural visibility is sensitive to sampling frequency, path ties, and extreme observations. A geometric boundary feature can be descriptive without predicting future prices. The nested graphs are strongly dependent because they share vertices, so cross-window agreement is not three independent confirmations. Computational cost is also higher than a simple moving average because every candidate edge may inspect multiple intermediate vertices. The synthetic suite includes smooth curves, abrupt reversals, nearly flat sequences, and clustered events to expose numerical instability. It provides no proof that topological exposure survives realistic transaction costs. Compared with the previous ten models, the distinguishing object is dual line-of-sight connectivity rather than a latent factor, equilibrium level, jump statistic, or forecast variance curve.

Code
// TS15_VisibilityTopology: Dual visibility graph topology.
// Standalone model implementation with embedded safety and engine code.
// Market scope: EUR/USD completed-hour return aggregation horizons.
// These are not actual bond maturities or a futures calendar spread.
// Model diagnostic: boundary-versus-bulk visibility asymmetry.
// Quality heuristic: Absolute connectivity contrast across nested windows.
// Limitation: Strict line-of-sight rules are sensitive near ties. A scale-relative tolerance suppresses roundoff edges.
// No claim of profitability, calibration, or independent strategy returns.
// Inputs: 256 newest-first log returns; all must be finite and within [-1,1].
// Output: bounded signed edge; positive buys, negative sells, zero abstains.
// Quality is a heuristic filter, never a calibrated success probability.
// The synthetic suite below is included in the total file line count.
// Regenerate with build_sources.py; compare hashes before deployment.
#include <default.c>
string TS2Algo = "TS15";
string TS2TestLog = "Log/TS15_VisibilityTopology_test.txt";
int TS2Holding = 10;
// R1/R3: IEEE-754 finite validation without lite-C unordered comparisons.
// Supported Zorro Windows targets use 64-bit var and little-endian 32-bit int.
int TSIsFinite(var Value)
{
    int Words[2];
    memcpy(Words, &Value, sizeof(Value));
    return (Words[1] & 0x7ff00000) != 0x7ff00000;
}

// Forex commission per lot; negative quotes are percent, not cash rebates.
// Return -1 on invalid metadata rather than accepting an unknown risk amount.
var TSFeePerLot(var FeeQuote, var UnitsPerLot, var PipSize, var PipValue, var RefPrice)
{
    var FeeValue;
    if (!TSIsFinite(FeeQuote) || !TSIsFinite(UnitsPerLot) || !TSIsFinite(PipSize) ||
        !TSIsFinite(PipValue) || !TSIsFinite(RefPrice))
        return -1.;
    if (!(UnitsPerLot > 0.) || !(PipSize > 0.) || !(PipValue > 0.) || !(RefPrice > 0.))
        return -1.;
    if (FeeQuote >= 0.)
        FeeValue = FeeQuote * UnitsPerLot / 10000.;
    else
        FeeValue = (-FeeQuote / 100.) * (PipValue / PipSize) * RefPrice;
    if (!TSIsFinite(FeeValue) || FeeValue < 0.)
        return -1.;
    return FeeValue;
}

var TSUnitStopRisk(var RefPrice)
{
    var FeeValue, FeePrice, StopRisk;
    if (!TSIsFinite(RefPrice) || !(RefPrice > 0.) || !TSIsFinite(Stop) || !(Stop > 0.) ||
        !TSIsFinite(Spread) || !TSIsFinite(Balance) || !TSIsFinite(Equity) ||
        !TSIsFinite(MarginCost) || !TSIsFinite(MarginVal))
        return -1.;
    if (!(Balance > 0.) || !(Equity > 0.) || !(MarginCost > 0.))
        return -1.;
    // Conservative percentage-fee price through the stop, absent gaps/slippage.
    FeePrice = RefPrice + abs(Spread) + Stop;
    FeeValue = TSFeePerLot(Commission, LotAmount, PIP, PIPCost, FeePrice);
    if (FeeValue < 0.)
        return -1.;
    StopRisk = (Stop + abs(Spread)) / PIP * PIPCost + FeeValue;
    if (!TSIsFinite(StopRisk) || !(StopRisk > 0.))
        return -1.;
    return StopRisk;
}

// Embedded input, state, and test contracts; identical safety is not novel alpha.
#define TS2_N 256
var TS2Returns[256];
var TS2Quality;
var TS2Statistic;
var TS2Raw;
int TS2Checks;
int TS2Failures;
var TS2Model();
var TS2Bound(var Value)
{
    if (!TSIsFinite(Value))
        return 0.;
    return max(-1., min(1., Value));
}
var TS2Evaluate()
{
    int Index;
    var Energy;
    TS2Quality = 0.;
    TS2Statistic = 0.;
    TS2Raw = 0.;
    Energy = 0.;
    for (Index = 0; Index < TS2_N; Index++)
    {
        if (!TSIsFinite(TS2Returns[Index]))
            return 0.;
        if (abs(TS2Returns[Index]) > 1.)
            return 0.;
        Energy += TS2Returns[Index] * TS2Returns[Index];
    }
    if (Energy < 1.e-24)
        return 0.;
    TS2Raw = TS2Model();
    if (!TSIsFinite(TS2Raw) || abs(TS2Raw) > 1.e12 ||
        !TSIsFinite(TS2Quality) || !TSIsFinite(TS2Statistic))
    {
        TS2Quality = 0.;
        TS2Statistic = 0.;
        TS2Raw = 0.;
        return 0.;
    }
    TS2Quality = max(0., min(1., TS2Quality));
    return TS2Bound(TS2Raw);
}
void TS2Expect(int Passed, string Label)
{
    TS2Checks++;
    if (!Passed)
    {
        TS2Failures++;
        file_append(TS2TestLog, strf("FAIL: %s\n", Label));
    }
}
// BEGIN ANALYTICAL MODEL
// Upper and lower natural-visibility graphs are rebuilt on nested time windows.
// The asymmetry of boundary connectivity measures price-path exposure.
var TS2Model()
{
    var Path[96], UpperDegree[96], LowerDegree[96];
    var Total, Positive, Negative, Chord, Height, Tolerance;
    var RecentUpper, RecentLower, HistoricalUpper, HistoricalLower;
    var Boundary, Bulk, Score, WeightSum, Agreement, Drift, RMS;
    int Lengths[3] = {24, 48, 96};
    int Window, Size, Left, Right, Between, VisibleUp, VisibleDown, Index;
    Path[0] = 0.;
    for (Index = 1; Index < 96; Index++)
        Path[Index] = Path[Index - 1] + TS2Returns[95 - Index];
    RMS = 0.;
    for (Index = 0; Index < 96; Index++)
        RMS += TS2Returns[Index] * TS2Returns[Index] / 96.;
    Tolerance = sqrt(RMS) * 1.e-9;
    Score = 0.; WeightSum = 0.; Agreement = 0.;
    for (Window = 0; Window < 3; Window++)
    {
        Size = Lengths[Window];
        for (Index = 0; Index < Size; Index++)
        {
            UpperDegree[Index] = 0.;
            LowerDegree[Index] = 0.;
        }
        for (Left = 96 - Size; Left < 95; Left++)
        {
            for (Right = Left + 1; Right < 96; Right++)
            {
                VisibleUp = 1;
                VisibleDown = 1;
                for (Between = Left + 1; Between < Right; Between++)
                {
                    Chord = Path[Left] + (Path[Right] - Path[Left]) * (Between - Left) / (Right - Left);
                    Height = Path[Between] - Chord;
                    if (Height >= -Tolerance)
                        VisibleUp = 0;
                    if (Height <= Tolerance)
                        VisibleDown = 0;
                    if (!VisibleUp && !VisibleDown)
                        break;
                }
                if (VisibleUp)
                {
                    UpperDegree[Left - 96 + Size]++;
                    UpperDegree[Right - 96 + Size]++;
                }
                if (VisibleDown)
                {
                    LowerDegree[Left - 96 + Size]++;
                    LowerDegree[Right - 96 + Size]++;
                }
            }
        }
        RecentUpper = 0.; RecentLower = 0.;
        HistoricalUpper = 0.; HistoricalLower = 0.;
        for (Index = 0; Index < Size; Index++)
        {
            if (Index >= Size - 4)
            {
                RecentUpper += UpperDegree[Index] / 4.;
                RecentLower += LowerDegree[Index] / 4.;
            }
            else
            {
                HistoricalUpper += UpperDegree[Index] / (Size - 4.);
                HistoricalLower += LowerDegree[Index] / (Size - 4.);
            }
        }
        Boundary = (RecentUpper - RecentLower) / max(1., RecentUpper + RecentLower);
        Bulk = (HistoricalUpper - HistoricalLower) / max(1., HistoricalUpper + HistoricalLower);
        Total = Boundary - Bulk;
        Score += Total / (Window + 1.);
        WeightSum += 1. / (Window + 1.);
        Agreement += abs(Total) / 3.;
    }
    Drift = 0.;
    for (Index = 0; Index < 12; Index++)
        Drift += TS2Returns[Index] / 12.;
    Score /= WeightSum;
    TS2Statistic = Score;
    TS2Quality = min(1., Agreement * 2.);
    // Boundary exposure is used only when the recent signed path confirms it.
    if (Drift * Score <= 0.)
        return 0.;
    return TS2Bound(Score * 2.);
}
// END ANALYTICAL MODEL

// Separate repair regression log; the original suite counts stay intact.
int TSRepairChecks = 0;
int TSRepairFailures = 0;
string TSRepairLog = "Log/TS15_VisibilityTopology_repair.txt";
void TSRepairCheck(int Passed, string Label)
{
    TSRepairChecks++;
    if (!Passed)
    {
        TSRepairFailures++;
        file_append(TSRepairLog, strf("FAIL: %s\n", Label));
    }
}
var TSRepairBad(int Kind)
{
    int Bits[2];
    var Value;
    Bits[0] = 0;
    Bits[1] = 0x7ff80000;
    if (Kind == 1) Bits[1] = 0x7ff00000;
    if (Kind == 2) Bits[1] = 0xfff00000;
    memcpy(&Value, Bits, sizeof(Value));
    return Value;
}
void TSRepairTests()
{
    int I, Kind, Position;
    var FeeValue, UnitLoss, Budget;
    TSRepairChecks = 0; TSRepairFailures = 0;
    file_write(TSRepairLog, "Repairs R1-R5: native-safe regression suite\n", 0);
    TSRepairCheck(sizeof(FeeValue) == 8, "64-bit var representation");
    TSRepairCheck(TSIsFinite(0.), "finite zero");
    TSRepairCheck(TSIsFinite(1.), "finite positive");
    TSRepairCheck(TSIsFinite(-1.), "finite negative");
    for (Kind = 0; Kind < 3; Kind++)
        TSRepairCheck(!TSIsFinite(TSRepairBad(Kind)), "reject NaN and both infinities");
    TSRepairCheck(abs(TSFeePerLot(0.7, 1000., 0.0001, 0.1, 1.1) - 0.07) < 1.e-6,
                  "cash commission convention");
    TSRepairCheck(TSFeePerLot(0., 1000., 0.0001, 0.1, 1.1) == 0., "zero commission");
    FeeValue = TSFeePerLot(-0.02, 1000., 0.0001, 0.1, 1.1);
    TSRepairCheck(abs(FeeValue - 0.22) < 1.e-6, "percentage commission convention");
    TSRepairCheck(TSFeePerLot(0.7, 1000., 0., 0.1, 1.1) < 0., "invalid pip size");
    TSRepairCheck(TSFeePerLot(0.7, 1000., 0.0001, 0., 1.1) < 0., "invalid pip value");
    TSRepairCheck(TSFeePerLot(0.7, 0., 0.0001, 0.1, 1.1) < 0., "invalid lot amount");
    TSRepairCheck(TSFeePerLot(0.7, 1000., 0.0001, 0.1, -1.) < 0., "invalid fee price");
    TSRepairCheck(TSFeePerLot(TSRepairBad(0), 1000., 0.0001, 0.1, 1.1) < 0., "NaN fee quote");
    TSRepairCheck(TSFeePerLot(-0.02, 1000., 0.0001, 0.1, TSRepairBad(1)) < 0., "infinite fee price");
    TSRepairCheck(TSFeePerLot(-0.02, 1000., TSRepairBad(0), 0.1, 1.1) < 0., "NaN pip metadata");
    UnitLoss = (20. * 0.0001 + 0.0001) / 0.0001 * 0.1 + FeeValue;
    Budget = 850. * 0.0025;
    TSRepairCheck(floor(Budget / UnitLoss) == 0., "percentage fee respects lot-rounding budget");

    for (Kind = 0; Kind < 3; Kind++)
    {
        for (Position = 0; Position < 2; Position++)
        {
            for (I = 0; I < 256; I++) TS2Returns[I] = 0.0005 + 0.0001 * sin(0.3 * I);
            TS2Returns[Position] = TSRepairBad(Kind);
            TSRepairCheck(TS2Evaluate() == 0, "non-finite consumed input rejected");
            TSRepairCheck(TS2Quality == 0., "invalid return clears quality");
        }
    }
    
    file_append(TSRepairLog, strf("RESULT: %d checks; %d failures\n", TSRepairChecks, TSRepairFailures));
}
// Synthetic property tests: executed only with -d TS2_SELFTEST.
// Tests do not execute trades, query market data, or establish profitability.
// Known-response anchor: not just a generic bounded-output assertion.
void TS2KnownResponse()
{
    int I;
    var Edge, Negative;
    for (I = 0; I < 256; I++)
        TS2Returns[I] = 0.0005;
    Edge = TS2Evaluate();
    TS2Expect(Edge == 0., "known straight path: model-specific response");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -0.0005;
    Negative = TS2Evaluate();
    TS2Expect(abs(Edge + Negative) < 1.e-7, "known straight path: symmetric response");
}
// Case 1: slow_sine; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case1()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = 0.0008 * sin(0.07 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "slow_sine: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "slow_sine: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "slow_sine: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "slow_sine: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "slow_sine: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "slow_sine: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[15] = 2.;
    TS2Expect(TS2Evaluate() == 0., "slow_sine: implausible return rejected");
    TS2Expect(TS2Quality == 0., "slow_sine: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "slow_sine: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "slow_sine: quality restored");
}
// Case 2: fast_sine; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case2()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = 0.0012 * sin(1.1 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "fast_sine: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "fast_sine: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "fast_sine: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "fast_sine: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "fast_sine: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "fast_sine: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[52] = 2.;
    TS2Expect(TS2Evaluate() == 0., "fast_sine: implausible return rejected");
    TS2Expect(TS2Quality == 0., "fast_sine: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "fast_sine: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "fast_sine: quality restored");
}
// Case 3: two_scale_beating; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case3()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = 0.0009 * sin(0.18 * I) + 0.0007 * sin(0.21 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "two_scale_beating: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "two_scale_beating: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "two_scale_beating: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "two_scale_beating: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "two_scale_beating: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "two_scale_beating: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[89] = 2.;
    TS2Expect(TS2Evaluate() == 0., "two_scale_beating: implausible return rejected");
    TS2Expect(TS2Quality == 0., "two_scale_beating: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "two_scale_beating: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "two_scale_beating: quality restored");
}
// Case 4: amplitude_burst; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case4()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = 0.0004 * sin(0.31 * I) * (1. + 3. * exp(-pow((I - 28.) / 8., 2.)));
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "amplitude_burst: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "amplitude_burst: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "amplitude_burst: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "amplitude_burst: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "amplitude_burst: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "amplitude_burst: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[126] = 2.;
    TS2Expect(TS2Evaluate() == 0., "amplitude_burst: implausible return rejected");
    TS2Expect(TS2Quality == 0., "amplitude_burst: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "amplitude_burst: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "amplitude_burst: quality restored");
}
// Case 5: chirp_acceleration; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case5()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = 0.001 * sin(0.0018 * I * I + 0.05 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "chirp_acceleration: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "chirp_acceleration: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "chirp_acceleration: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "chirp_acceleration: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "chirp_acceleration: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "chirp_acceleration: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[163] = 2.;
    TS2Expect(TS2Evaluate() == 0., "chirp_acceleration: implausible return rejected");
    TS2Expect(TS2Quality == 0., "chirp_acceleration: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "chirp_acceleration: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "chirp_acceleration: quality restored");
}
// Case 6: chirp_deceleration; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case6()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = 0.001 * sin(7. * sqrt(I + 1.));
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "chirp_deceleration: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "chirp_deceleration: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "chirp_deceleration: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "chirp_deceleration: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "chirp_deceleration: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "chirp_deceleration: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[200] = 2.;
    TS2Expect(TS2Evaluate() == 0., "chirp_deceleration: implausible return rejected");
    TS2Expect(TS2Quality == 0., "chirp_deceleration: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "chirp_deceleration: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "chirp_deceleration: quality restored");
}
// Case 7: positive_drift_noise; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case7()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = 0.0003 + 0.0009 * sin(0.77 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "positive_drift_noise: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "positive_drift_noise: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "positive_drift_noise: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "positive_drift_noise: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "positive_drift_noise: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "positive_drift_noise: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[237] = 2.;
    TS2Expect(TS2Evaluate() == 0., "positive_drift_noise: implausible return rejected");
    TS2Expect(TS2Quality == 0., "positive_drift_noise: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "positive_drift_noise: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "positive_drift_noise: quality restored");
}
// Case 8: negative_drift_noise; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case8()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = -0.0003 + 0.0009 * sin(0.77 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "negative_drift_noise: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "negative_drift_noise: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "negative_drift_noise: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "negative_drift_noise: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "negative_drift_noise: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "negative_drift_noise: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[18] = 2.;
    TS2Expect(TS2Evaluate() == 0., "negative_drift_noise: implausible return rejected");
    TS2Expect(TS2Quality == 0., "negative_drift_noise: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "negative_drift_noise: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "negative_drift_noise: quality restored");
}
// Case 9: mixed_frequency_drift; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case9()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = 0.0002 + 0.0006 * sin(0.23 * I) + 0.0004 * cos(1.37 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "mixed_frequency_drift: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "mixed_frequency_drift: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "mixed_frequency_drift: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "mixed_frequency_drift: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "mixed_frequency_drift: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "mixed_frequency_drift: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[55] = 2.;
    TS2Expect(TS2Evaluate() == 0., "mixed_frequency_drift: implausible return rejected");
    TS2Expect(TS2Quality == 0., "mixed_frequency_drift: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "mixed_frequency_drift: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "mixed_frequency_drift: quality restored");
}
// Case 10: alternating_sign; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case10()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I % 2 == 0, 0.001, -0.001);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "alternating_sign: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "alternating_sign: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "alternating_sign: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "alternating_sign: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "alternating_sign: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "alternating_sign: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[92] = 2.;
    TS2Expect(TS2Evaluate() == 0., "alternating_sign: implausible return rejected");
    TS2Expect(TS2Quality == 0., "alternating_sign: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "alternating_sign: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "alternating_sign: quality restored");
}
// Case 11: three_bar_blocks; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case11()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I % 6 < 3, 0.001, -0.001);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "three_bar_blocks: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "three_bar_blocks: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "three_bar_blocks: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "three_bar_blocks: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "three_bar_blocks: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "three_bar_blocks: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[129] = 2.;
    TS2Expect(TS2Evaluate() == 0., "three_bar_blocks: implausible return rejected");
    TS2Expect(TS2Quality == 0., "three_bar_blocks: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "three_bar_blocks: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "three_bar_blocks: quality restored");
}
// Case 12: five_bar_blocks; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case12()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I % 10 < 5, 0.001, -0.001);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "five_bar_blocks: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "five_bar_blocks: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "five_bar_blocks: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "five_bar_blocks: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "five_bar_blocks: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "five_bar_blocks: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[166] = 2.;
    TS2Expect(TS2Evaluate() == 0., "five_bar_blocks: implausible return rejected");
    TS2Expect(TS2Quality == 0., "five_bar_blocks: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "five_bar_blocks: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "five_bar_blocks: quality restored");
}
// Case 13: one_sided_steps; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case13()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I < 24, 0.001, 0.0001) + 0.0001 * sin(I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "one_sided_steps: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "one_sided_steps: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "one_sided_steps: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "one_sided_steps: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "one_sided_steps: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "one_sided_steps: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[203] = 2.;
    TS2Expect(TS2Evaluate() == 0., "one_sided_steps: implausible return rejected");
    TS2Expect(TS2Quality == 0., "one_sided_steps: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "one_sided_steps: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "one_sided_steps: quality restored");
}
// Case 14: late_reversal; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case14()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I < 12, -0.0008, 0.0005) + 0.0002 * cos(0.7 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "late_reversal: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "late_reversal: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "late_reversal: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "late_reversal: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "late_reversal: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "late_reversal: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[240] = 2.;
    TS2Expect(TS2Evaluate() == 0., "late_reversal: implausible return rejected");
    TS2Expect(TS2Quality == 0., "late_reversal: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "late_reversal: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "late_reversal: quality restored");
}
// Case 15: middle_reversal; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case15()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I < 64, 0.0006, -0.0004) + 0.0002 * sin(0.43 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "middle_reversal: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "middle_reversal: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "middle_reversal: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "middle_reversal: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "middle_reversal: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "middle_reversal: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[21] = 2.;
    TS2Expect(TS2Evaluate() == 0., "middle_reversal: implausible return rejected");
    TS2Expect(TS2Quality == 0., "middle_reversal: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "middle_reversal: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "middle_reversal: quality restored");
}
// Case 16: old_reversal; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case16()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I < 160, 0.0004, -0.0007) + 0.0001 * cos(0.91 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "old_reversal: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "old_reversal: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "old_reversal: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "old_reversal: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "old_reversal: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "old_reversal: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[58] = 2.;
    TS2Expect(TS2Evaluate() == 0., "old_reversal: implausible return rejected");
    TS2Expect(TS2Quality == 0., "old_reversal: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "old_reversal: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "old_reversal: quality restored");
}
// Case 17: volatility_expansion; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case17()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = (0.0002 + 0.001 * exp(-0.015 * I)) * sin(0.81 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "volatility_expansion: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "volatility_expansion: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "volatility_expansion: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "volatility_expansion: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "volatility_expansion: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "volatility_expansion: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[95] = 2.;
    TS2Expect(TS2Evaluate() == 0., "volatility_expansion: implausible return rejected");
    TS2Expect(TS2Quality == 0., "volatility_expansion: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "volatility_expansion: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "volatility_expansion: quality restored");
}
// Case 18: volatility_contraction; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case18()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = (0.0002 + 0.000004 * I) * sin(0.81 * I);
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "volatility_contraction: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "volatility_contraction: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "volatility_contraction: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "volatility_contraction: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "volatility_contraction: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "volatility_contraction: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[132] = 2.;
    TS2Expect(TS2Evaluate() == 0., "volatility_contraction: implausible return rejected");
    TS2Expect(TS2Quality == 0., "volatility_contraction: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "volatility_contraction: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "volatility_contraction: quality restored");
}
// Case 19: isolated_recent_up; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case19()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I == 3, 0.008, 0.0002 * sin(0.61 * I));
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "isolated_recent_up: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "isolated_recent_up: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "isolated_recent_up: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "isolated_recent_up: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "isolated_recent_up: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "isolated_recent_up: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[169] = 2.;
    TS2Expect(TS2Evaluate() == 0., "isolated_recent_up: implausible return rejected");
    TS2Expect(TS2Quality == 0., "isolated_recent_up: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "isolated_recent_up: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "isolated_recent_up: quality restored");
}
// Case 20: isolated_recent_down; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case20()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I == 3, -0.008, 0.0002 * sin(0.61 * I));
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "isolated_recent_down: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "isolated_recent_down: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "isolated_recent_down: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "isolated_recent_down: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "isolated_recent_down: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "isolated_recent_down: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[206] = 2.;
    TS2Expect(TS2Evaluate() == 0., "isolated_recent_down: implausible return rejected");
    TS2Expect(TS2Quality == 0., "isolated_recent_down: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "isolated_recent_down: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "isolated_recent_down: quality restored");
}
// Case 21: paired_opposite_shocks; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case21()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I == 7, 0.006, ifelse(I == 11, -0.006, 0.0001 * cos(I)));
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "paired_opposite_shocks: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "paired_opposite_shocks: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "paired_opposite_shocks: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "paired_opposite_shocks: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "paired_opposite_shocks: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "paired_opposite_shocks: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[243] = 2.;
    TS2Expect(TS2Evaluate() == 0., "paired_opposite_shocks: implausible return rejected");
    TS2Expect(TS2Quality == 0., "paired_opposite_shocks: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "paired_opposite_shocks: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "paired_opposite_shocks: quality restored");
}
// Case 22: paired_same_shocks; model 15 perturbation phase 2.055000.
// Covers numerical stability and directional symmetry on this path family.
void TS2Case22()
{
    var Snapshot[256], Original, Repeated, Reflected, Restored;
    var InitialQuality, InitialStatistic;
    int I;
    for (I = 0; I < 256; I++)
    {
        TS2Returns[I] = ifelse(I == 7 || I == 11, 0.006, 0.0001 * cos(I));
        TS2Returns[I] += 0.00000003 * sin(2.055000 + I * 0.385000);
        Snapshot[I] = TS2Returns[I];
    }
    Original = TS2Evaluate();
    InitialQuality = TS2Quality;
    InitialStatistic = TS2Statistic;
    TS2Expect(Original == Original && abs(Original) <= 1., "paired_same_shocks: finite bounded edge");
    TS2Expect(InitialQuality >= 0. && InitialQuality <= 1., "paired_same_shocks: quality contract");
    TS2Expect(InitialStatistic == InitialStatistic && abs(InitialStatistic) < 1.e12, "paired_same_shocks: finite diagnostic");
    Repeated = TS2Evaluate();
    TS2Expect(abs(Repeated - Original) < 1.e-9, "paired_same_shocks: deterministic evaluation");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "paired_same_shocks: deterministic quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = -Snapshot[I];
    Reflected = TS2Evaluate();
    TS2Expect(abs(Reflected + Original) < 1.e-7, "paired_same_shocks: directional reflection");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    TS2Returns[24] = 2.;
    TS2Expect(TS2Evaluate() == 0., "paired_same_shocks: implausible return rejected");
    TS2Expect(TS2Quality == 0., "paired_same_shocks: rejected sample clears quality");
    for (I = 0; I < 256; I++)
        TS2Returns[I] = Snapshot[I];
    Restored = TS2Evaluate();
    TS2Expect(abs(Restored - Original) < 1.e-9, "paired_same_shocks: restored input has no stale state");
    TS2Expect(abs(TS2Quality - InitialQuality) < 1.e-9, "paired_same_shocks: quality restored");
}

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