I built three tools for Quantinuum's guppy/HUGR stack. Along the way I found six real bugs. I've been working with guppylang — Quantinuum's Python-embedded quantum programming language, compiling to HUGR, running on their Selene simulator and trapped-ion hardware. It's a young ecosystem, and I wanted to build things that were actually useful, not just demos. That meant treating correctness as the whole point, not an afterthought — every formula cited to its source, every claim about co...