After one day — reconstruct

• Draw the three-column inventory: states, operations, observations.
• State the adequacy tiebreak in order: reachability, used laws, second consumer.
• For the latest chapter, name its carrier, operation, one law, one counterexample, and one refusal case.

After one week — discriminate

• Sum type or machine: are there merely alternatives, or do events constrain movement between them?
• Generation fence or idempotency key: are you deciding which result may publish, or whether a receiver has already performed an operation?
• Delta or event: does the value describe a change to apply, or a durable fact from which views may be folded?
• Monoid or semilattice: may order matter while grouping does not, or must order and duplication both be irrelevant?
• Zipper or mutable cursor: does the cursor carry an immutable reconstruction path, or point into shared storage?

After one month — transfer

Choose unfamiliar code from a cache, compiler, request handler, editor, or device protocol. Without using chapter vocabulary at first:

1. enumerate states, operations, owners, and observations;
2. find one reachable contradiction or ambiguous transition;
3. propose two structures that fit;
4. reject one with the adequacy tiebreak;
5. state two laws and minimize a counterexample to each;
6. sketch a pure core and an effect handler; and
7. describe the evidence an advisory detector could report without claiming certainty.

Return to the contents only after making the attempt.

References

1. “Karpicke and Blunt, “Retrieval Practice Produces More Learning than Elaborative Studying with Concept Mapping”.” — evidence motivating retrieval rather than rereading.
2. “Cepeda et al., “Spacing Effects in Learning”.” — evidence that useful spacing depends on the retention interval rather than one magic schedule.