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GERO Research

A mathematical view of
AI reliability.

Original research and independent analysis of the problems frontier laboratories are naming — translated into mathematical questions, assurance mechanisms and tests that can fail.

128published materials
3frontier research groups
1rule: evidence before confidence

The name

Graph Evaluation &
Reliability Orchestrator.

GERO organizes independent checks around AI-generated claims and keeps every conclusion inside the boundary of its evidence.

G

Graph

Map assumptions, evidence and conclusions.

E

Evaluation

Apply bounded checks to necessary claims.

R

Reliability

Expose contradictions and unresolved risk.

O

Orchestrator

Coordinate models, tools and expert review.

The journal

Ideas, sources, experiments.

We do not copy laboratory articles. We link to the primary source, state what it reports, separate our inference and propose a falsifiable GERO response.

170 publications

Independent Numerical Audit

MLX arctan: finite weighted derivatives collapse to zero after intermediate overflow

In Apple MLX CPU float32, arctan differentiation forms 1+x² before division. For finite x=-2^64 and seed=-2^120, x² overflows and the JVP/VJP becomes signed zero although the correctly rounded result is -0.00390625. A scale-aware research candidate reduces 352 discrepancies per tested layout to zero, with documented higher-order residuals.

Independent Numerical Audit

bond_pricing 0.7.3 ignores immediate-start annuity payments

A documented payment-timing flag is ignored: two immediate-start payments with PV 210 and a 10% rate are calculated as 121 instead of 110. Actual package reproduction, explicit cash-flow reference and a proposed correction.

Independent Numerical Audit

FinancePy Merton jump pricing: a zero probability can erase an option value

Current-source Merton jump pricing returns 0 instead of about 23.50587 under a finite-input stress test. 112 scenarios, 52/0/52 discrepancies with candidate/restoration, and a measured synthetic worksheet consequence. The affected module is absent from the released 1.1.2 wheel.

Independent Numerical Audit

FinancePy floating lookback calls: a finite price becomes unavailable

A valid floating lookback call worth about 54.03 becomes unavailable because a power overflows before multiplication by a tiny probability. A local log-space candidate removes 52 failing public calls on a 600-row grid; restoration reproduces all 52.

Independent Numerical Audit

MLX erf: a finite gradient becomes infinity before damping is applied

Native MLX CPU float32 execution returns an infinite derivative action where 1.32834399e38 is representable. A synthetic guarded update is skipped; a bounded first-derivative candidate permits it. Extreme tails and second derivatives remain limited.

Independent Numerical Audit

Endowment variance scales the benefit twice in actuarialmath

The benefit scale is applied twice to endowment variance. In a synthetic report, the native portfolio estimate changes from 41,862.13 to 6,606.12 and a 7,000-limit decision flips. Exact-payout replay: 483 → 0 → 483 mismatches across 1,300 scenarios.

Independent Numerical Audit

Strata: a zero-volatility Hessian prevents custom-model option pricing

NaN second derivatives interrupt the native price extrapolator through a documented custom-model interface. Direct failures180->0->180 in866 input rows; downstream constructor failures6->0->6 in21 input rows. Synthetic constant-volatility fixture; default Hagan/CMS path excluded; no bank/customer loss measured.

Independent Numerical Audit

PyLoan replaces an explicit 100 payment with a 919.10 final payment

PyLoan 0.7.2 overrides a specified annuity payment at maturity. A synthetic schedule pays 919.10 instead of 100; a targeted candidate removes 408 payment-cap violations in 864 scenarios. Separate rounding differences and unchanged upstream test failures are retained.

Independent Numerical Audit

Strata returns zero implied volatility for a positive option price

For a synthetic option price of 1, Strata 2.12.74 returns normal implied volatility 0 instead of 2.5066282746 when the initial guess is zero. A local initializer correction removes 864 failures in 1,750 observations; restoring the source restores them. Reported first as issue 2796.

Independent Numerical Audit

nntrainer SplitLayer leaves later channels unwritten

A valid width split of four values leaves two output positions unwritten. Actual C++ full-prefill tests:4,320 coordinate mismatches become zero with a local channel-loop correction; restoring the original code restores the same errors.

Independent Numerical Audit

FinancePy Vasicek pricing loses the small-mean-reversion limit

At a positive mean-reversion parameter of 1e-8, a finite bond price near 0.6167242 becomes infinity. Across 1,350 positive-parameter scenarios: 527 original discrepancies, zero with a local correction, and the same 527 after restoring the original code.

Independent Numerical Audit

MLX median overflows while averaging finite central values

Two copies of 60000 have median 60000. Native MLX float16 returns infinity. A bounded local correction removes 540 incorrect outputs across 7488 observations; restoring the original code restores every failure.

Independent Numerical Audit

ConstantForce whole-life insurance ignores the benefit amount

A benefit of 100,000 returns 0.4 instead of 40,000 in an educational actuarial library. A missing multiplier explains 120 failures across 144 observations; a local correction and mutation replay isolate the cause.

Independent Numerical Audit

FinancePy Merton calibration depends on the monetary unit

The same synthetic firm changes from 7.77% to 95.49% calculated default probability when monetary units change. Normalizing before calibration removes 94 failed round trips across 120 scenarios; residual solver statuses remain disclosed.

LLM Experiment · Archival mirror

Spark-X2.5-1.7B: exact fee bases and half-up rounding study

An AI-operated study of 12 authored arithmetic exercises, with original model outputs, exact references and separate answer-delivery scores. This is an LLM experiment, not an implementation-bug report.

Independent Numerical Audit

actuarialmath whole-life variance squares the mean twice

The mean and second moment are correct, but an extra square produces the wrong variance. A local correction resolves 54 discrepancies across 96 independently checked synthetic cases.

Independent Numerical Audit

FinancePy BAW pricing divides by zero at a zero rate

A finite zero-rate coefficient is formed as 0/0, and a nearby put can exceed the boundary solver's iteration limit. Released-wheel reproduction, analytic limit, independent CRR control and a green upstream correction.

Independent Numerical Audit

FinancePy Act/365L can fail when an optional date is omitted

A documented two-date call can dereference the absent reference-period end when an annual interval reaches February 29. Released-wheel reproduction, independent 91/366 control and submitted correction.

Technical Note · Service demonstration

Checking the rules behind financial calculations

A public Fineract case with 25 common checks, scoped candidate corrections, reproducible sources and a 40-second customer overview. Synthetic component evidence; customer impact is not established.

Independent Numerical Audit

Finite FP16 Inputs Become Zero in MLX GroupNorm

Standard GroupNorm returns zeros for finite FP16 inputs because a sum of squares overflows before division. A CPU research patch preserves channel grouping: 45 main-suite failures become zero, with 41 compatibility checks passing.

Independent Numerical Audit

One FP16 Batch Corrupts MLX BatchNorm Running Variance

A finite float16 batch makes the default running variance infinite, leaving later evaluation at zero. A CPU research patch changes 102 main-suite failures to zero, with 33 compatibility checks passing. Existing corrupted state is not restored.

Independent Numerical Audit

Scale Changes the Gradient: MLX arctan2

For atan2(C*t,C), the derivative at t=1 must remain 0.5. MLX returns zero or infinity at extreme scales. A research patch passes 1368 native comparisons; both failed intermediate patches are preserved.

Independent Numerical Audit

A Nonzero Derivative Becomes Zero: MLX expm1

At x=-20, reverse mode returns zero for a derivative near 0.20611536. A local VJP repair plus the known exp control passes 216 native comparisons; the VJP-only patch can regress float64.

Technical Note

A Missing Transpose in MLX Quantized Gradients

With transpose=False, affine gather_qmm miscomputes scale and bias gradients. A local C++ orientation repair passes 205 scenarios and 379 checks; the measured quadratic update then lowers the loss.

Technical Note

Sorted Indices, Wrong Gradients: MLX Gather

Valid sorted-index calls produce incorrect gather_mm and affine gather_qmm gradients. A bounded local FP32 CPU repair passes 69 scenarios and 626 checks; quantized FP16 fallback remains a limitation.

Technical Note

Orthogonal Is Not Symmetric: MLX Hadamard Gradients

MLX uses the forward Hadamard transform in reverse differentiation for nonsymmetric factors 20 and 28. A local C++ repair passes 64 scenarios and 624 checks; measured energy steps confirm the correction.

Technical Note

A Missing Gradient in MLX Block Updates

A strict C++ scatter_max/min block update loses a winning gradient. Independent finite differences confirm the reference; a minimal extent correction passes 26 targeted checks.

Technical Note

When Dropout Sends Two Gradients to One Input

A native C++ nntrainer case study: zero-rate Dropout forwards correctly but misroutes multiple input gradients. Finite differences, a local patch and 19 passing tests.

Frontier Lab Watch

A machine-checked proof still needs a statement contract

Anthropic's Fermat formalization shows the scale now possible in Lean; the remaining assurance problem is preserving meaning, provenance and dependency scope from source theorem to checked root.

Technical Note

When Causal Attention Sees the Future

A reproducible nntrainer causal-mask report: future values affect earlier outputs. Native tests, a local repair and an upstream issue are available.

Technical Note

When Small Losses and Gradients Disappear

Reproduced BCE and logaddexp failures in MLX and nntrainer, with mathematical references, tested local patches and downloadable evidence.

Frontier Lab Watch

Attribution graphs still need a semantic contract

Mechanistic interpretability can expose computational structure, but the map is partial and the meaning assigned to it remains a scientific claim.

Frontier Lab Watch

Monitoring reasoning is a stability problem

OpenAI's monitorability evaluations raise a systems question: will a useful safety signal remain informative after training, scaling and distribution shift?

Frontier Lab Watch

Self-correction is two problems, not one

Google Research separates finding a mistake from repairing it; GERO turns that distinction into separate evidence contracts.

Evidence standard

Source. Interpretation. Test. Boundary.

Every frontier brief preserves those four layers. Read the editorial and evidence standard or follow new work through RSS.