Practice Lanes and Book Reinforcement

P01–P20 in the four practice pages form the required progression. Their feedback is separate. Reuse related lab evidence instead of writing duplicate reports. Lesson drills provide targeted repair or optional depth.

Gap	Selective assignment	Return with
Unsure what a refactor preserves	Refactoring, Defining Refactoring and The Two Hats	Observations and intentional changes separated
Smell automatically determines a fix	Refactoring, code smells	Hypothesis, counterexample and competing design
One-provider interface automatically removed	Good Code, Bad Code, Interfaces	Present benefit and carrying-cost decision
Inheritance judged by names	Good Code, Bad Code, inheritance risks	Parent contract and violating client
Lost guarantees across a boundary	Good Code, Bad Code, code contracts	Input/error/state/ownership contract

Locate these through the reading guide and the Refactoring book index. No invented exercise numbers, forced renames or minimum comment-deletion counts are required. More reading volume is not evidence of design judgment.