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Measure Twice, Generate, Then Look Again

TL;DR for operators A CAD assistant that writes code once and hopes for the best is not an engineering workflow. It is a raffle with syntax highlighting. IterCAD is interesting because it treats CAD generation and editing as an iterative operating loop: read the drawing, generate CadQuery code, execute it in a sandbox, inspect compiler and geometric feedback, revise, and stop only when the model has evidence that the shape is right.1 The paper’s practical contribution is not “AI can design parts now.” That would be the usual confetti cannon, and mercifully not the correct lesson. The better lesson is that useful CAD automation needs closed-loop verification, localized visual grounding, and evaluation metrics that count failures instead of quietly hiding them in the basement. ...

June 29, 2026 · 21 min · Zelina
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Binding Obligations: Why AI Fails When the Relationships Slip

TL;DR for operators AI systems are getting better at producing outputs that look structured: code, CAD, diagrams, workflows, compliance memos, procurement recommendations, and decision traces. That is not the same as keeping the structure right. Two recent arXiv papers make this point from opposite ends of the problem. One looks inside language models and finds evidence for a compact retrieval-conditioned rebinding mechanism: the model does not necessarily rewrite its whole internal world after a state change; it can preserve old representations and redirect retrieval when the answer is needed.1 The other builds an engineering benchmark for Text-to-CAD and shows that models can pass earlier surface gates — executable code, plausible geometry — while still failing the practical tests of functionality, manufacturability, and assemblability.2 ...

June 18, 2026 · 19 min · Zelina
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Bending the Beam, Not the Brain: What RL with Perfect Rewards Still Can’t Teach LLMs

Beams are honest objects. Push them, load them, move their supports, and they obey equilibrium equations without theatrical ambiguity. Language models, unfortunately, are less well-behaved. That is what makes BeamPERL a useful paper. It does not test LLM reasoning on a vague benchmark where “correctness” means pleasing a judge, matching a rubric, or sounding sufficiently graduate-school. It asks a compact reasoning model to solve a classical beam statics task: calculate support reactions for a loaded beam. The answers can be checked by a symbolic solver. The reward can be exact. No vibes, no partial credit, no “the answer feels plausible.”1 ...

March 5, 2026 · 16 min · Zelina
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Code That Thinks, Models That Don’t: What SymPyBench Reveals About LLM Scientific Reasoning

Calculator. That is the boring object hiding inside many “AI reasoning” debates. In technical work, the uncomfortable question is not whether a language model can explain a formula with academic confidence. It is whether the model can still get the answer right after the numbers change, the wording shifts, the unit conversion becomes annoying, and no multiple-choice option politely waves from the corner saying, “Pick me.” ...

December 8, 2025 · 16 min · Zelina