Constructions

How does a sentence become a model another person can inspect? Constructions teaches the craft of formalization through one small example about water, then carries the same habits into geometry, evidence, a literary parable, standards and measurement. Eighteen chapters introduce objects, assertions, rules, four states of support, explanations, constraints, exceptions and human judgment. Readers then return to sources, editions and dates, work with quantities and dependencies, and learn to choose checks that distinguish competing models. The final chapter follows a small model from its question and assumptions to the materials a recipient needs to examine it. Code excerpts and recorded expectations make each step concrete, while the prose separates a model’s answer from the truth of its premises. This first English edition contains the complete reading text. The companion includes checked examples for npm-installed @arxo/cli 0.2.4, checked on macOS ARM64. All 383 selected scenarios and 50 printed command blocks passed. Third-party components retain their stated licences; the OpenStax-based material is offered for noncommercial use. Editorial and source-language checks were completed with Codex and Astra.

18 chapters, with a prologue and an epilogue. Edition 2026.10.Original prose and illustrations are offered under CC BY 4.0. Third-party materials retain their own terms; OpenStax excerpts and adaptations are for noncommercial use under CC BY-NC-SA 4.0.Edition details.