How this works. This chapter is read live from grammars/three-lenses-64/grammar.json — the same grammar behind the library and Lenses. Nothing here is duplicated content: edit that grammar and this course updates with it. See course/three-lenses.manifest.json for the chapter ordering and companion-grammar links. Note: the source grammar's chapter items currently carry names and keywords but empty sections — this course renders honestly empty chapter bodies until that content is written; see the field report for why.