Exercise Lanes and Optional Depth

The required exercise set is P01–P20 on the four practice pages, seven labs, three experiments and the bounded project. See the module path. Do not add a second hidden quota of katas, languages, classes or mistakes.

After a weak gate, choose one targeted reading from the reading guide, solve a fresh case, and explain how it transfers. The practice key is separate so independent attempts remain possible.

Optional depth, beyond the stated workload:

• Port one contract to another language and document dispatch, equality and iterator differences.
• Add a bounded history with a documented eviction rule and recheck undo/redo at the boundary.
• Implement a parser for the small Boolean language with token/depth limits and diagnostics.
• Explore asynchronous notification with explicit capacity, cancellation and shutdown.
• Study durable outbox/consumer behavior later with an actual storage and crash model.

Optional work does not replace a missing required competency. Avoid treating a distributed-systems extension as something the local models already guarantee.

Required runtime comparison

Also complete runtime trace practice, the EventBus/Editor comparison lab and BD1–BD6. Preserve the extra close/ownership and immutable-history evidence. Reuse shared core explanations; the different cancellation/no-op traces must remain explicit. The combined allocation is 110–161 hours, including 10–16 hours for this comparison rather than an additional duplicate full extension.