webAI-Official/TwIL-LM2

TEXT GENERATIONPricing:Input $0.32 / Cached $0.016 / Output $1.6Concurrent Unit Cost:1Model Size:2BQuant:BF16Context Size:32kPublished:Sep 29, 2026License:otherArchitecture:Transformer0.0K Featherless Exclusive Cold

webAI-Official/TwIL-LM2 is a 2.53 billion parameter decoder-only transformer model, built from ibm-granite/granite-3.3-2b-instruct. Developed by webAI-Official, it is specifically optimized for formal logic tasks, demonstrating strong performance in areas like Lean formalization and rule induction. The model achieves a macro gate score of 0.4178 on in-domain formal logic benchmarks and offers fast decoding speeds, making it suitable for specialized reasoning applications.

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TwIL-LM2: A Specialized Formal Logic Reasoning Model

TwIL-LM2 is a 2.53 billion parameter model developed by webAI-Official, derived from ibm-granite/granite-3.3-2b-instruct. It is highly specialized for formal logic tasks, including FOL translation, entailment, semantic parsing, Lean formalization, and critique.

Key Capabilities & Performance

  • Exceptional Formal Logic Performance: Achieves a macro gate score of 0.4178 on in-domain formal logic benchmarks, ranking fourth among twelve compared models, ahead of larger alternatives like LFM2.5-8B-A1B and Granite-4.1-3B.
  • Competitive in Specific Logic Lanes: Ranks fourth on lean_formalize token-F1 (0.5159) and ahead of TwIL-LM3 on rule_induction (0.3292).
  • High Decoding Speed: Decodes at 21,369 tokens/s on an H100, making it 1.57x faster than TwIL-LM3 due to its Granite architecture base.
  • Efficient Resource Usage: With 2.53B parameters, it runs efficiently, including GGUF builds for CPU deployment (e.g., Q4_K_M at 1.44 GiB).
  • Long Context Window: Inherits a 131,072-token context window from its base model, though evaluations were conducted with shorter generation budgets.

Limitations & Intended Use

  • Not a General Assistant: This model is not designed for general-purpose tasks or strict output formatting. It performs poorly on strict-output metrics (e.g., strict MCQ accuracy 0.0000, strict-7 score 0.1214) and general held-out benchmarks.
  • No Safety Tuning: Lacks specific safety tuning or instruction-following alignment beyond its base model.
  • Non-Commercial License: Released under the webAI Non-Commercial License ver. 1.0.

TwIL-LM2 is ideal for applications requiring robust performance in formal logic reasoning where speed and specialized accuracy are paramount, rather than broad general knowledge or strict output adherence.