Learn Coding USA: two-writer reference simulation
Run with Python 3.9 or later: python3 reference_simulator.py --out results
No dependencies, Git commands, network access or repository changes. The program writes three CSVs inside the chosen output directory. It enumerates all six schedules preserving each writer's read-before-write order. An atomic conditional update is an assumed operation in the model, not an implementation for concurrent threads or distributed hosts. Objects have a single parent; rejected proposals remain stored but are not accepted. No retries, merges, durability, consensus, garbage collection or performance timing is modeled. Assertions check exact expected totals. The outputs supplied here were executed on 11 November 2026.
