HNHiroyuki Nakahatainblog.iroha1203.dev·Jul 18 · 16 min readSAGA's Cape of Good Hope: The One Cent That Cohomology CaughtTL;DR This is the sequel to the SAGA theorem article. Last time, I gave the "locally correct, globally broken" phenomenon a theorem, proved in Lean 4. This time I took that theorem out into the real 00
HNHiroyuki Nakahatainblog.iroha1203.dev·Jul 7 · 15 min readThe Rising Sea of Software Engineering — Rebuilding the Discipline on Algebraic GeometryAI now writes code faster than humans can review it. That is not a prediction; it is the daily experience of most engineering teams. And here is the other daily experience: no matter how much you inve30
HNHiroyuki Nakahatainblog.iroha1203.dev·Jul 2 · 19 min readThe SAGA Theorem: The Day Software Architecture Became Genuine Algebraic GeometryTL;DR Every module passes review, yet the system as a whole is broken. This "locally correct, globally inconsistent" phenomenon has a name in mathematics: cohomology, specifically H^1. AAT (Algebrai20
HNHiroyuki Nakahatainblog.iroha1203.dev·May 31 · 19 min readAtom Is All You Need: Read a Codebase as an Atom Map, Not a Dependency GraphTL;DR In the AI era, architecture analysis cannot stop at reading code as files, functions, imports, and dependency graphs. We need to observe the smallest units that carry architectural meaning. I ca10
HNHiroyuki Nakahatainblog.iroha1203.dev·May 22 · 14 min readForecast Cone: A Grand Theorem for Computable Software EvolutionTL;DR This article starts from the ForecastCone in Software Field Theory (SFT), then reads modularity, technical debt, review, governance, and learning as parts of one research program. The goal is si00
