Via20/blind-spots-frontier-optimization
Technical Challenge: Symbolic Drift & Constraint Decay in Frontier LLMs 1. Executive Summary & Background When deploying AI for core engineering, economic, and mathematical optimization tasks (such as Karush-Kuhn-Tucker conditions or Lagrangian multipliers), calculations require rigorous multi-step invariant tracking. Drawing from practical experience building optimization pipelines, we identify an underexplored capability gap in current models: Symbolic Drift and… See the full description on the dataset page: https://huggingface.co/datasets/Via20/blind-spots-frontier-optimization.
Technical Challenge: Symbolic Drift & Constraint Decay in Frontier LLMs
1. Executive Summary & Background
When deploying AI for core engineering, economic, and mathematical optimization tasks (such as Karush-Kuhn-Tucker conditions or Lagrangian multipliers), calculations require rigorous multi-step invariant tracking. Drawing from practical experience building optimization pipelines, we identify an underexplored capability gap in current models: Symbolic Drift and Constraint Decay.
Unlike human analysts who maintain external working memory or strict symbolic invariants, autoregressive language models treat derivations as next-token distributions. As derivation length increases:
- Coefficients mutate silently across intermediate paragraphs.
- Constraints vanish or fail to enforce complementary slackness (\mu \ge 0).
- Algebraic shortcuts mask missing intermediate arithmetic steps, leading to high residual constraint violations.
2. Systematic Evaluation Setup
- Model Evaluated:
Qwen/Qwen2.5-3B-Instruct(~3.09 Billion parameters, hosted on Hugging Face). - Environment: Google Colab (Free T4 GPU runtime, FP16 precision via Hugging Face Transformers & PyTorch).
- Evaluation Suite: Custom dataset of multi-step constrained quadratic programs and portfolio risk minimization problems requiring exact rational fraction arithmetic and boundary verification.
3. Empirical Observations & Failure Modes
4. Detailed Case Study: Concrete Failure Trace Analysis (cqp_01)
To understand how the model fails under the hood, we audited the generated text for test case cqp_01:
- The Model's Optimal Point: The model successfully derived the coordinate candidate (x^, y^) = (6/5, 7/5) = (1.2, 1.4).
- Primal Constraint Verification:
- Testing equality (2x - y = 1): 2(1.2) - 1.4 = 2.4 - 1.4 = 1.0 (Satisfied).
- Testing inequality (x + 2y \ge 4): 1.2 + 2(1.4) = 1.2 + 2.8 = 4.0 (Meets boundary equality).
- The Smoking Gun (Arithmetic Hallucination & Symbolic Strain): When evaluating the objective function f(x, y) = 3x^2 + 2y^2 - 4x + 6y + 7 at this point using rational fractions, the model generated:
[ = 3(36/25)^2 + 2(49/25)^2 - 24/5 + 42/5 + 7 ][ = 108/25 + 98/25 - 120/25 + 210/25 + 175/25 ][ = 491/25 = 19.64 ]
The Audit: Summing the numerators correctly yields 108 + 98 - 120 + 210 + 175 = 471, not 491. The model suffered from a hidden arithmetic hallucination at the final summation stage while maintaining flawless linguistic and markdown formatting. This proves that models can mimic proof structures perfectly while failing multi-step arithmetic invariants.
5. Proposed Path Forward
To bridge this gap without scaling model size, we propose:
- Neuro-Symbolic Sandboxing (RLVR): Fine-tuning models via Reinforcement Learning with Verifiable Rewards to output executable symbolic code blocks (e.g.,
SymPy) for intermediate arithmetic and constraint verification. - State-Tracking Attention Registers: Architectural buffers dedicated to pinning variable definitions and active inequalities across deep context windows to prevent symbolic decay.
6. Repository Artifacts
run_eval.py: Complete Google Colab execution script.evaluation_results.json: Raw model outputs, token counts, and execution logs across all categories.
