## Chapter 18 — A test-folder restore is not the letters ### Lesson map Lesson 18. Map, example, EX064. ```mermaid flowchart TD M["May restore cell is 0"] --> C["Prose: nobody knew how"] J["June restore cell is 1"] --> T["Prose: a test folder"] T --> Q{"Does the 1 name patient letters?"} Q -->|No| K["May's zero stays"] ``` Practice changes a later cell. It does not edit the earlier zero. ### Logical drawing ```text restore index: 2 May 0, June 1, July 1 object restored in prose: a test folder not the object: patient-letters/ or old-backup.zip ``` ### Learning outcomes After this chapter, you should be able to: 1. Keep May's restore zero. 2. Bound June's one to a test folder in prose. 3. Refuse a letter restore and a zip deletion dressed up as the same event. ### 18.1 Index 2 flips. The letters are a different object. The restore task is index 2. May stores `0`. The prose says the miss happened because nobody knew how. June stores `1` after Leila practised with a test folder. July stores `1`. The script's miss line for May names "check backups restored" and the June line does not. Nothing in the cell identifies the folder, the file, or a byte count. `patient-letters/` is a sharing triple, not a restore operand. `old-backup.zip` is the archive that was later deleted. Deleting an unneeded zip does not exercise a restore, and a test-folder practice does not show that the letters could be returned. The two labs do not share a row identifier, so a reader cannot join them by key. A successful June practice leaves May's zero where it is. Rewriting May to `1` would raise May's numerator and shorten its miss list. That rewrite is not in the file. No backup product, no location, and no duration are printed. ### 18.2 Worked example | Claim | Fit | Decision | |---|---|---| | May missed the restore task | Index 2 is 0 | Keep | | June's practice used a test folder | Prose | Keep, unnamed beyond that | | "Patient letters were restored in June." | No such operand | Reject | | "May was corrected to 1 after the practice." | The vector is unchanged | Reject | > **Synthetic case.** The test folder has no further name. ### Errors and limits Do not join the zip's deletion to index 2. They answer different questions. ### Apply - **EX064 — Which object.** A note changes May's restore bit to 1, says the patient letters were restored, and treats the zip deletion as that restore. What stays in the file? *Rubric:* 3 = May stays 0 and June stays 1 at index 2; the practice object stays an unnamed test folder; letters and the zip are different objects; do not edit the vector;; 2 = the bits stay and the letters claim is refused;; 1 = one bit;; 0 = none. ### Continue studying — lesson 18 (chapter 18 of 20) [← Chapter 17](#ch-17) · [Course chapter index](../SUBJECTS.md) · [Chapter 19 →](#ch-19) Continue to the next authored lesson. ## Worked answers **EX064.** May's restore cell stays 0 and June's stays 1. The practice object stays a test folder. Patient letters and `old-backup.zip` are different objects. The vector is not edited.