Cohort construction with provenance
A worked example | Step 1: install a base table | Step 2: apply root-level exclusions | Step 3: branch into sub-cohorts | The freeze rule | Step 4: derive cached artifacts | Step 5: inspect the cohort tree | Step 6: hand off downstream | Schemas | CONSORT diagrams | How the cache decides what to recompute | Mutation contract (summary) | Performance notes