|

webAI Releases TwIL-LM: A 1.7B and 3B Formal-Logic Model Family for Autoformalization on Local Hardware

ByRicardo

webAI has launched TwIL-LM, a two-model family of formal-logic reasoners at 1.7B and 3B parameters. The 3B member, TwIL-LM3, is a merged fine-tune of SmolLM3-3B; the 1.7B member is a PEFT LoRA adapter for SmolLM2-1.7B-Instruct. Both goal autoformalization: translating English into first-order logic and checking whether or not a conclusion follows from its premises. Both run regionally, with a 1.06 GB quantized construct for the 1.7B and a 1.78 GiB Q4_K_M GGUF for the 3B. webAI’s announcement frames the discharge round beating gpt-oss-120b on 4 of 5 formal-reasoning lanes.

Is it deployable?

Partially. Non-commercial use solely, as of now.

Both checkpoints ship beneath the webAI Non-Commercial License ver. 1.0. Revenue-generating deployment requires a separate settlement with webAI.

  • Company degree: any dimension. The 3B Q4_K_M GGUF is 1.78 GiB and runs on CPU or 4 GB of VRAM. The 1.7B Q4_K_M is 1.06 GB.
  • Industries: compliance and RegTech, monetary providers, healthcare and pharma, authorized and contract operations, formal-methods analysis. webAI positions native execution for environments the place knowledge can’t go away the system.
  • Applications: first-order logic (FOL) translation, entailment classification over premise units, pure language to structured question, Lean formalization drafting and critique, and a verifier layer that checks a bigger mannequin’s output.

How TwIL-LM3 was constructed?

Four phases sit on prime of the bottom mannequin. LoRA supervised fine-tuning on an artificial formal-logic corpus. Checkpoint fusion, averaging intermediate SFT checkpoints in parameter area. WiSE-FT interpolation again towards the pretrained base at λ = 0.25. Then MGPO, an entropy-weighted GRPO stage run towards a programmatic verifier. The printed checkpoint is step 2071.

That λ is load-bearing: solely 1 / 4 of the fine-tuned delta is retained. A sibling arm that skipped the interpolation scored increased in-domain, at macro gate 0.515, however gave again roughly twelve factors of held-out functionality. webAI didn’t publish that arm.