Organizations: Fudan University, China · Shanghai Artificial Intelligence Laboratory, China · University of Cambridge, UK · Nankai University, China · UNC-Chapel Hill, US · University of Oxford, UK
Recovering analytical solutions of physical fields from visual observations is a fundamental yet underexplored capability for AI-assisted scientific reasoning. We study visual-to-symbolic analytical solution inference (ViSA) for two-dimensional linear steady-state fields: given field visualizations (and first-order derivatives) plus minimal auxiliary metadata, the model must output a single executable SymPy expression with fully instantiated numeric constants. We introduce ViSA-R2 and align it with a self-verifying, solution-centric chain-of-thought pipeline that follows a physicist-like pathway: structural pattern recognition solution-family (ansatz) hypothesis parameter derivation consistency verification. We also release ViSA-Bench, a VLM-ready synthetic benchmark covering 30 linear steady-state scenarios with verifiable analytical/symbolic annotations, and evaluate predictions by numerical accuracy, expression-structure similarity, and character-level accuracy. Using an 8B open-weight Qwen3-VL backbone, ViSA-R2 outperforms strong open-source baselines and the evaluated closed-source frontier VLMs under a standardized protocol.
Figure 2: Overall pipeline for ViSA dataset construction and evaluation.
Figure 3: Overall pipeline for feature extraction, evidence matching, parameter inference, and synthesize high-quality reasoning chain.
VLM
LLM-only
Model
Overall
Char
Struct
Num
Overall
Char
Struct
Num
GPT-5.2 ( OpenAI, 2025 )
0.474
0.290
0.768
0.370
0.200
0.273
0.323
0.295
Grok-4-1-Fast ( xAI, 2025a )
0.242
0.169
0.613
0.048
0.116
0.217
0.195
0.176
Claude-Haiku-4-5 ( Anthropic, 2025a )
0.316
0.204
0.638
0.167
0.159
0.221
0.261
0.221
ViSA-R2 (Ours)
0.512
0.482
0.860
0.385
–
–
–
–
Table 1: Overall comparison in VLM vs. LLM settings. We report the OverallScore and its three components for both VLM inputs and LLM-only inputs under the standardized protocol in § 4.1 . We only include models that successfully return valid outputs for more than 90% of the test instances.
Model
Input
Overall
Success
ViSA-R2 framework
Vision
0.512
100.0%
Claude-Haiku-4-5 ( Anthropic, 2025a )
Vision
0.316
93.3%
Claude Sonnet 4.5 ( Anthropic, 2025c )
Text
0.352
63.3%
Gemini-3-Pro ( Google DeepMind, 2025 )
Vision
0.572
60.0%
Claude Opus 4 ( Anthropic, 2025b )
Text
0.135
26.7%
DeepSeek-R1 ( DeepSeek, 2025 )
Text
0.915
10.0%
Table 2: Comparison of representative models by overall score and success rate.
Variant
Char
Struct
Num
Overall
Qwen-3-8B-baseline
0.191
0.616
0.210
0.328
w/o CoT alignment
0.016
0.053
0.017
0.024
w/ CoT alignment (ViSA-R2)
0.482
0.860
0.385
0.512
ViSA-R2 framework
0.480
0.842
0.780
0.669
Table 3: Ablation B. CoT alignment and coefficient refinement.
Category
Scenario Name
Operator
Sing.
#Samples
Electrostatics
Point Charge Potential
Laplacian
✓
500
Electric Dipole Potential
Laplacian
✓
500
Coulomb Potential Field
Laplacian
×
500
Heat Transfer
Gaussian Heat Source
Laplacian
×
500
Multi-Gaussian Heat Sources
Laplacian
×
500
Thermal Boundary Layer
Laplacian
×
500
Table 4: Distribution of scenarios in the training dataset by operator type and physical domain.
A user pointing their phone at a supermarket shelf and asking "Which soda has the least sugar?" poses a difficult challenge for current visual Al assistants. Such queries require not only object recognition, but explicit set-based reasoning such as filtering, comparison, and aggregation. Standard endto-end MLLMs often fail at these tasks because they lack an explicit mechanism for compositional logic. We propose treating visual reasoning as Visual Program Synthesis, where the model first generates a symbolic program that is executed by a separate engine grounded in visual scenes. We also introduce Set-VQA, a new benchmark designed specifically for evaluating set-based visual reasoning. Experiments show that our approach significantly outperforms state-of-the-art baselines on complex reasoning tasks, producing more systematic and transparent behavior while substantially improving answer accuracy. These results demonstrate that program-driven reasoning provides a principled alternative to black-box visual-language inference.
Zehua Cheng, Wei Dai, Wenhu Zhang +2
Department of Computer Science, University of Oxford · Department of Computer Science and Engineering, Hong Kong University of Science and Technology · Institute of Logic and Computation, TU Wien
Visual reasoning tasks require a system to jointly perceive visual content and apply formal relational constraints---a combination that neither pure neural nor purely symbolic approaches handle well in isolation. This paper proposes a Neuro-Symbolic (NeSy) framework that closes this gap by tightly coupling a Vision-Language Model (VLM) for automatic First-Order Logic (FOL) rule induction with a Dynamic Logic Tensor Network (D-LTN) for differentiable rule verification, in a closed iterative feedback loop. The VLM receives a small set of labelled visual examples and proposes candidate FOL rules conforming to a strict grammar (Think); the D-LTN is automatically assembled from these rules at runtime and evaluates them grounding on CNN-produced visual embeddings (Verify); and verification failures are fed back to guide the VLM's next hypothesis (Revise). Evaluated on the ViSudo-PC benchmark across four visual domains (MNIST, EMNIST, KMNIST, FMNIST), the system induces valid Sudoku constraint rules using only three training examples as visual context. The proposed method achieves AUC scores matching or outperforming previous methods (NeuPSL, LTN), showing the potential for automatic rule discovery through VLM. Code is available at https://github.com/homayoun-afshari/nesy.
Homayoun Afshari, Pietro Basci, Alessandro Russo +1
Politecnico di Torino Department of Control and Computer Engineering Turin, Italy
Electrical circuit analysis requires more than recognizing components in an image. A solver must ground symbols and labels, recover latent topology, select a physical model, formulate coupled equations, propagate intermediate quantities, and preserve units, signs, directions, and phase conventions. We introduce \benchmark, a benchmark of 1,000 authentic textbook problems for evaluating this complete long-horizon visual-to-symbolic reasoning process. Each problem pairs one or more circuit diagrams with a self-contained question, a typed or semantically specified answer, and a reference worked solution. An evidence-first construction pipeline aligns questions, figures, and solutions, while a reasoning-oriented taxonomy organizes problems by circuit type and dependency depth. Evaluation combines conservative typed scoring with identity-blinded multi-model semantic consensus, retaining every problem in the denominator. Across three commercial chatbot systems and six open-source multimodal large language models, the highest-scoring system reaches 84.8% accuracy. However, performance consistently deteriorates on long-horizon problems, and qualitative analysis exposes persistent failures in topology-to-target binding, physical conventions, and late-stage output propagation. \benchmark{} provides a focused testbed for measuring whether multimodal models can transform technical visual evidence into sustained, physically valid symbolic reasoning. Code are available at GitHub - CircuitReason/CircuitReason1K.
Xinqi Yang, Kang An, Tengyue Wang +8
Shanghai Jiao Tong University · South China University of Technology · ModelBest +6