diff --git a/M02_MasterTemplete/M02_Doc_Sk_Path.py b/M02_MasterTemplete/M02_Doc_Sk_Path.py
index e740a5101..b662f415c 100644
--- a/M02_MasterTemplete/M02_Doc_Sk_Path.py
+++ b/M02_MasterTemplete/M02_Doc_Sk_Path.py
@@ -26,6 +26,8 @@ from M02_MasterTemplete import M02_MyMachine_Draft as draft
 from M02_MasterTemplete import M02_Sangeun_Copy as skc
 from M02_MasterTemplete import M02_Sangeun_Doc as sd
 
+import master_doc_cover as mcv  # noqa: E402 — 기계 덮음(836-1 · scripts 길 = dc)
+
 MAX = 2_000_000  # 문서 글 크기(바이트) 상한
 JOBS = (skc.PRICE, skc.REGEN)
 
@@ -133,8 +135,19 @@ def edited(copy: dict, body: dict, key: str, sk: dict | None = None) -> dict:
         *dc.calls(out["문서"]),
         *(c for d in out.get("끊음", {}).values() for c in dc.calls(d)),
     ]
+    try:  # 기계 덮음(836-1) — 몸 검사 · 원본과 같은 칸 · 안 부르는 기계 뺌(가져온 식 = 검사만)
+        if dim.is_imported(sk):
+            got = mcv.clean(out["문서"].get(mcv.COVER))
+            rest = {k: v for k, v in out["문서"].items() if k != mcv.COVER}
+            out["문서"] = {**rest, mcv.COVER: got} if got else rest
+    except ValueError as e:
+        raise _bad(str(e)) from e
     if not dim.is_imported(sk):
         out["부름"] = dc.closure(dc.over(out), calls, copy.get("부름"))
+        try:
+            out["문서"] = mcv.prune_doc(out["문서"], dc.ml.Links(dc.over(out), dc.docs_of(out)))
+        except ValueError as e:
+            raise _bad(str(e)) from e
         out = gap.fill(out)  # 셈이 읽은 줄 가운데 사본 없는 것 = 지금 값으로 박음(822-1)
         out = draft.renew(out)  # 기계 창 초안으로 만든 · 고친 내 기계 = 새 값(827-1)
     out["따로"] = True
diff --git a/common_util/common_util_formula_doc_calc.ts b/common_util/common_util_formula_doc_calc.ts
index 5aafeccab..fe33fc79d 100644
--- a/common_util/common_util_formula_doc_calc.ts
+++ b/common_util/common_util_formula_doc_calc.ts
@@ -25,6 +25,7 @@ import {
   type Node,
   type Rule,
 } from "./common_util_formula_doc";
+import { coverDoc, coverOf as machineCover, type Cover } from "./common_util_formula_doc_cover";
 
 const EPS = 1e-7; // B09_Estimation_Calc_Base EPS 와 같음
 const DEEP = 20;
@@ -137,6 +138,7 @@ class Run {
     readonly given: Record<string, unknown>,
     readonly stack: string[],
     readonly memo: Memo,
+    readonly cover: Cover, // 기계 덮음(836-1) — 맨 위 문서 칸 · 부름에 얹음
   ) {
     for (const v of doc.변수 ?? []) this.vars.set(varId(v), v);
     for (const l of doc.식 ?? []) this.lines.set(String(l.기호 ?? ""), l.식);
@@ -364,8 +366,13 @@ class Run {
       .sort()
       .map((k) => `${k}=${plainText(given[k])}`)
       .join("|")}`;
-    if (!this.memo.has(memoKey))
-      this.memo.set(memoKey, calcDoc(doc, this.links, given, [...this.stack, key], this.memo));
+    if (!this.memo.has(memoKey)) {
+      const shaped = coverDoc(doc, given, this.cover);
+      this.memo.set(
+        memoKey,
+        calcDoc(shaped, this.links, given, [...this.stack, key], this.memo, this.cover),
+      );
+    }
     const got = this.memo.get(memoKey) as DocAnswer;
     if (!got.셈됨) {
       // 값 없음(결과 빈 입력 · 표 줄 없음) = 빈 값 · 그 밖(표지) = 멈춤
@@ -565,16 +572,17 @@ export function rulesOf(doc: FormulaDoc): Record<string, Rule | string> {
 
 const STOP_KINDS = ["기호 꼴", "연결 꼴", "금액 줄", "끝수", "겹침"];
 
-/** 수식 문서 셈 — given = {변수 열쇠: 값}(단가산출 부름이 넘긴 입력) · 예외 없음 */
+/** 수식 문서 셈 — given = {변수 열쇠: 값}(단가산출 부름이 넘긴 입력) · cover = 기계 덮음(없음 = 문서 칸) · 예외 없음 */
 export function calcDoc(
   doc: FormulaDoc,
   links: DocLinks,
   given: Record<string, unknown> = {},
   stack: string[] = [],
   memo: Memo = new Map(),
+  cover?: Cover,
 ): DocAnswer {
   if (!stack.length && doc.키) stack = [String(doc.키)]; // 제 키 — 저를 부르면 순환
-  const run = new Run(doc, links, given, stack, memo);
+  const run = new Run(doc, links, given, stack, memo, cover ?? machineCover(doc));
   for (const one of check(doc)) if (STOP_KINDS.includes(one.갈래)) run.marks.push(one);
   const rules = rulesOf(doc);
   for (const name of [...run.lines.keys(), ...run.vars.keys()]) if (name) run.get(name);
diff --git a/common_util/common_util_formula_doc_cover.ts b/common_util/common_util_formula_doc_cover.ts
new file mode 100644
index 000000000..b1093e794
--- /dev/null
+++ b/common_util/common_util_formula_doc_cover.ts
@@ -0,0 +1,298 @@
+/* =============================================================================
+ * common_util_formula_doc_cover.ts
+ * 기계 덮음(PLAN 836-1 · 요구 846 · 849 · 850 · 853) — 단가산출 안 기계 내부 값 고침(사본 줄은 그대로 · 고친 것만 따로)
+ *   자리 = 문서 칸 `기계덮음` {기계 입력 글: {값?: {칸: 값}, 조종원?: [{키, 인}], 잡품?: [{줄? | 키?, 이름?, 수량?, 율}]}}
+ *     기계 입력 글 = 부름 입력 `기계` 값(따옴표 뗌 · 원문번호 · 개인 EQP…) — 같은 기계 줄 여럿 = 한 벌
+ *     값 = 기계 식이 읽는 기계 칸(요소 `EQ:{S_기계}` 칸 — 조종원 · 조종원직종 · 잡재료율 빼고) · 조종원 = 인력 줄(노임 키 · 인/일) ·
+ *     잡품 = 재료 줄(율 % · 줄 = 그 금액 줄 단가 · 수량 따름(기본) · 키 = 고른 재료 요소) · 원본과 같은 칸 = 없음(`prune`)
+ *   셈 규칙(`coverDoc`) = 계산기가 기계 식을 부를 때 그 기계 덮음을 얹은 문서로 셈 — 덮음 없음 = 문서 그대로(금액 전후 같음)
+ *   파이썬 · TS 짝 — 짝 = resources/master_data/scripts/master_doc_cover.py · 거울 시험 test_836_1_machine_cover.py
+ *   · 화면 · DOM · fetch 없음
+ * ========================================================================== */
+
+import {
+  names,
+  parse,
+  symId,
+  varId,
+  type DocVar,
+  type FormulaDoc,
+  type MoneyLine,
+} from "./common_util_formula_doc";
+
+export const COVER = "기계덮음";
+/** 값 칸에서 빼는 기계 칸 — 줄(조종원 · 잡품)로 다룸 */
+export const NOT_VALUE = ["조종원", "조종원직종", "잡재료율"];
+const HOUR = "Q_시간환산";
+/** 조종원 줄을 새로 넣을 때(조종원 없는 식) 시간환산 — GC000267 과 같은 꼴(건설품셈 공통 1-1-3 2) */
+const HOUR_VARS: DocVar[] = [
+  {
+    열쇠: "Q_분자^표", 기호: "Q", 아래: "분자", 위: "표", 이름: "건설기계 조종원 노임 시간 환산 계수.분자", 단위: "",
+    연결: { 갈래: "표", 표: "CC000336", 조건: { 구분: "'시간환산'" }, 칸: "분자" },
+  },
+  {
+    열쇠: "Q_분모^표", 기호: "Q", 아래: "분모", 위: "표", 이름: "건설기계 조종원 노임 시간 환산 계수.분모", 단위: "",
+    연결: { 갈래: "표", 표: "CC000336", 조건: { 구분: "'시간환산'" }, 칸: "분모" },
+  },
+  { 열쇠: "시간환산", 기호: "Q", 아래: "시간환산", 위: "", 이름: "시간환산", 단위: "", 연결: { 갈래: "식" } },
+]; // prettier-ignore
+const HOUR_LINE = { 기호: HOUR, 식: "Q_분자^표 ÷ Q_분모^표" };
+
+export interface CrewRow {
+  키: string;
+  인: number;
+}
+export interface MiscRow {
+  줄?: string;
+  키?: string;
+  이름?: string;
+  단위?: string;
+  수량?: number;
+  율: number;
+}
+export interface MachineCover {
+  값?: Record<string, number | string>;
+  조종원?: CrewRow[];
+  잡품?: MiscRow[];
+}
+export type Cover = Record<string, MachineCover>;
+type Holder = FormulaDoc & { [COVER]?: Cover };
+
+const clone = <T>(v: T): T => JSON.parse(JSON.stringify(v)) as T;
+const plain = (n: number): string => String(Number(n.toPrecision(15)));
+
+export const coverOf = (doc: FormulaDoc | null | undefined): Cover => {
+  const got = (doc as Holder | null | undefined)?.[COVER];
+  return got && typeof got === "object" && !Array.isArray(got) ? got : {};
+};
+
+/** 부름 입력 → 기계 열쇠(따옴표 뗌) · 기계 입력 없음 = "" */
+export function machineKey(given: Record<string, unknown> | null | undefined): string {
+  const v = given?.기계;
+  if (v === undefined || v === null) return "";
+  const t = String(v).trim();
+  return /^'.*'$/.test(t) ? t.slice(1, -1) : t;
+}
+
+const namesOf = (text: unknown): string[] => {
+  if (text === null || text === undefined || String(text).trim() === "") return [];
+  try {
+    return names(parse(text));
+  } catch {
+    return [];
+  }
+};
+
+export interface CoverParts {
+  /** 값 칸 — 칸 이름 · 그 칸을 읽는 기호(차례 = 문서 변수 차례) */
+  fields: { 칸: string; ids: string[] }[];
+  /** 조종원 금액 줄 차례 · 사람 수 기호 */
+  crew: number[];
+  crewQty: Record<number, string>;
+  /** 잡품(잡재료비) 금액 줄 차례 · 율 기호 · 밑 재료 줄 차례 */
+  misc: number | null;
+  rate: string | null;
+  base: number[];
+}
+
+/** 기계 식 짜임 — 기계 칸 요소(`EQ:…{S_기계}…`) · 조종원 줄(노무비 · 수량이 칸 「조종원」) · 잡품 줄(재료비 누계 × 율) */
+export function partsOf(doc: FormulaDoc): CoverParts {
+  const eq = new Map<string, string>();
+  for (const v of doc.변수 ?? []) {
+    const l = v.연결 ?? {};
+    const k = String(l.키 ?? "");
+    if (l.갈래 === "요소" && k.startsWith("EQ:") && k.includes("{S_기계}") && l.칸)
+      eq.set(varId(v), l.칸);
+  }
+  const fields: CoverParts["fields"] = [];
+  for (const [id, col] of eq) {
+    if (NOT_VALUE.includes(col)) continue;
+    const at = fields.find((f) => f.칸 === col);
+    if (at) at.ids.push(id);
+    else fields.push({ 칸: col, ids: [id] });
+  }
+  const lines = doc.금액 ?? [];
+  const crew: number[] = [];
+  const crewQty: Record<number, string> = {};
+  let misc: number | null = null;
+  let rate: string | null = null;
+  lines.forEach((l, i) => {
+    const q = namesOf(l.수량).find((n) => eq.get(n) === "조종원");
+    if (l.비목 === "노무비" && q) {
+      crew.push(i);
+      crewQty[i] = q;
+    }
+    const p = namesOf(l.단가);
+    const other = p.filter((n) => n !== "재료비");
+    if (misc === null && l.비목 === "재료비" && p.includes("재료비") && other.length === 1) {
+      misc = i;
+      rate = other[0];
+    }
+  });
+  const base =
+    misc === null
+      ? []
+      : lines.flatMap((l, i) => (i < misc! && l.비목 === "재료비" && !l.합밖 ? [i] : []));
+  return { fields, crew, crewQty, misc, rate, base };
+}
+
+type Vals = Record<string, unknown>;
+const num = (v: unknown): number | null => (typeof v === "number" && Number.isFinite(v) ? v : null);
+/** 요소 키 글의 구멍을 값으로 채움(`LB:{S_직종}` → `LB:1048`) */
+const fillKey = (text: string, vals: Vals): string =>
+  text.replace(/\{([^{}]+)\}/g, (_, h: string) => {
+    const v = vals[h];
+    return typeof v === "number" ? plain(v) : String(v ?? "");
+  });
+
+/** 원본(덮음 없음) 기본값 — 셈 답 값(`vals` = 그 기계로 셈한 원본 답 `값`) */
+export function defaultsOf(doc: FormulaDoc, vals: Vals): Required<MachineCover> {
+  const parts = partsOf(doc);
+  const lines = doc.금액 ?? [];
+  const vars = new Map((doc.변수 ?? []).map((v) => [varId(v), v]));
+  const 값: Record<string, number | string> = {};
+  for (const f of parts.fields) {
+    const v = vals[f.ids[0]];
+    if (typeof v === "number" || typeof v === "string") 값[f.칸] = v;
+  }
+  const 조종원 = parts.crew.flatMap((i) => {
+    const n = num(vals[parts.crewQty[i]]);
+    const sym = namesOf(lines[i].단가)[0];
+    const key = String(vars.get(sym ?? "")?.연결?.키 ?? "");
+    return n && key ? [{ 키: fillKey(key, vals), 인: n }] : [];
+  });
+  const r = parts.rate ? num(vals[parts.rate]) : null;
+  const 잡품 = r ? parts.base.map((i) => ({ 줄: String(lines[i].이름 ?? ""), 율: r })) : [];
+  return { 값, 조종원, 잡품 };
+}
+
+const canon = (v: unknown): string =>
+  JSON.stringify(v, (_, x: unknown) =>
+    x && typeof x === "object" && !Array.isArray(x)
+      ? Object.fromEntries(
+          Object.entries(x as Record<string, unknown>)
+            .filter(([, y]) => y !== undefined && y !== null && y !== "")
+            .sort(([a], [b]) => (a < b ? -1 : 1)),
+        )
+      : typeof x === "number"
+        ? Number(x.toPrecision(12))
+        : x,
+  );
+const sameVal = (a: unknown, b: unknown): boolean =>
+  typeof a === "number" && typeof b === "number"
+    ? Math.abs(a - b) <= 1e-9 * Math.max(1, Math.abs(a), Math.abs(b))
+    : String(a) === String(b);
+
+/** 원본과 같은 칸 · 줄을 뺀 덮음(바꿨다 되돌림 = 안 고침) · 다 빠지면 null */
+export function prune(entry: MachineCover, base: Required<MachineCover>): MachineCover | null {
+  const out: MachineCover = {};
+  const vals = Object.entries(entry.값 ?? {}).filter(
+    ([k, v]) =>
+      v !== null && v !== undefined && v !== "" && !(k in base.값 && sameVal(v, base.값[k])),
+  );
+  if (vals.length) out.값 = Object.fromEntries(vals);
+  if (entry.조종원 && canon(entry.조종원) !== canon(base.조종원)) out.조종원 = entry.조종원;
+  if (entry.잡품 && canon(entry.잡품) !== canon(base.잡품)) out.잡품 = entry.잡품;
+  return Object.keys(out).length ? out : null;
+}
+
+/** 덮음 한 기계 고침 → 문서 칸(원본 대조로 정리 · 비면 칸 지움) */
+export function putCover(
+  doc: FormulaDoc,
+  machine: string,
+  entry: MachineCover,
+  base: Required<MachineCover>,
+): void {
+  const box = doc as Holder;
+  const all = { ...coverOf(doc) };
+  const kept = prune(entry, base);
+  if (kept) all[machine] = kept;
+  else delete all[machine];
+  if (Object.keys(all).length) box[COVER] = all;
+  else delete box[COVER];
+}
+
+// ── 셈 규칙 ───────────────────────────────────────────────────────────
+/** 새 요소 기호(`w_조종원1` · `P_잡품1` — 문서에 없는 첫 번호) */
+function addVar(doc: FormulaDoc, sign: string, low: string, name: string, key: string): string {
+  const have = new Set([
+    ...(doc.변수 ?? []).map(varId),
+    ...(doc.식 ?? []).map((l) => String(l.기호 ?? "")),
+  ]);
+  let n = 1;
+  while (have.has(symId(sign, `${low}${n}`))) n++;
+  const 아래 = `${low}${n}`;
+  const id = symId(sign, 아래);
+  (doc.변수 ??= []).push({
+    열쇠: id, 기호: sign, 아래, 위: "", 이름: name, 단위: "", 연결: { 갈래: "요소", 키: key },
+  }); // prettier-ignore
+  return id;
+}
+
+function crewLines(doc: FormulaDoc, rows: CrewRow[]): MoneyLine[] {
+  const have = (doc.변수 ?? []).some((v) => varId(v) === HOUR) || (doc.식 ?? []).some((l) => l.기호 === HOUR); // prettier-ignore
+  if (rows.length && !have) {
+    const ids = new Set((doc.변수 ?? []).map(varId));
+    for (const v of HOUR_VARS) if (!ids.has(varId(v))) (doc.변수 ??= []).push(clone(v));
+    (doc.식 ??= []).push({ ...HOUR_LINE });
+  }
+  return rows.map((r) => ({
+    이름: "조종원",
+    단위: "인",
+    비목: "노무비",
+    수량: `${plain(r.인)} × ${HOUR}`,
+    단가: addVar(doc, "w", "조종원", "조종원 노임", r.키),
+  }));
+}
+
+function miscLines(doc: FormulaDoc, rows: MiscRow[], lines: MoneyLine[]): MoneyLine[] {
+  return rows.flatMap((r) => {
+    let price: string;
+    let qty: string;
+    let label = r.이름 ?? "";
+    if (r.키) {
+      price = addVar(doc, "P", "잡품", label || r.키, r.키);
+      qty = plain(r.수량 ?? 1);
+    } else {
+      const b = lines.find((l) => String(l.이름 ?? "") === r.줄);
+      if (!b || !b.단가) return [];
+      price = String(b.단가);
+      qty = r.수량 !== undefined && r.수량 !== null ? plain(r.수량) : `(${b.수량 ?? 1})`;
+      label ||= String(b.이름 ?? "");
+    }
+    return [{ 이름: "잡품", 규격: label, 단위: "", 비목: "재료비", 수량: `${qty} × ${plain(r.율)} ÷ 100`, 단가: price } as MoneyLine]; // prettier-ignore
+  });
+}
+
+/** 기계 식 문서에 그 기계 덮음을 얹음(새 문서) — 덮음 없음 = 그대로(같은 물건) */
+export function coverDoc(
+  doc: FormulaDoc,
+  given: Record<string, unknown> | null | undefined,
+  cover: Cover | null | undefined,
+): FormulaDoc {
+  const entry = cover?.[machineKey(given)];
+  if (!entry || !machineKey(given)) return doc;
+  const out = clone(doc) as FormulaDoc & { 쌓기?: unknown };
+  delete out.쌓기; // 금액 차례가 바뀜 — 기본 차림
+  const parts = partsOf(out);
+  for (const f of parts.fields)
+    if (entry.값 && f.칸 in entry.값)
+      for (const v of out.변수 ?? [])
+        if (f.ids.includes(varId(v))) v.연결 = { 갈래: "숫자", 값: entry.값[f.칸] };
+  const lines = out.금액 ?? [];
+  const crew = entry.조종원 ? crewLines(out, entry.조종원) : null;
+  const misc = entry.잡품 && (parts.misc !== null || entry.잡품.length) ? miscLines(out, entry.잡품, lines) : null; // prettier-ignore
+  const gone = new Set([...(crew ? parts.crew : []), ...(misc && parts.misc !== null ? [parts.misc] : [])]); // prettier-ignore
+  const tail = lines.findIndex((l) => l.비목 === "경비");
+  const end = tail < 0 ? lines.length : tail;
+  const crewAt = parts.crew.length ? parts.crew[0] : end;
+  const miscAt = parts.misc ?? end;
+  const next: MoneyLine[] = [];
+  for (let i = 0; i <= lines.length; i++) {
+    if (crew && i === crewAt) next.push(...crew);
+    if (misc && i === miscAt) next.push(...misc);
+    if (i < lines.length && !gone.has(i)) next.push(lines[i]);
+  }
+  out.금액 = next;
+  return out;
+}
diff --git a/resources/master_data/scripts/master_doc_calc.py b/resources/master_data/scripts/master_doc_calc.py
index 6f0b661b3..8c13f2f2d 100644
--- a/resources/master_data/scripts/master_doc_calc.py
+++ b/resources/master_data/scripts/master_doc_calc.py
@@ -16,6 +16,7 @@ import math
 from decimal import ROUND_DOWN, ROUND_HALF_UP, ROUND_UP, Decimal, InvalidOperation
 
 import master_doc as md
+import master_doc_cover as mcv
 
 COSTS, BUNDLE = md.COSTS, md.BUNDLE
 EPS = 1e-7  # B09_Estimation_Calc_Base.EPS 와 같음
@@ -79,8 +80,9 @@ def number(v):
 
 # ── 셈 한 벌 ──────────────────────────────────────────────────────────
 class _Run:
-    def __init__(self, doc: dict, links, given: dict | None, stack: tuple, memo: dict):
+    def __init__(self, doc: dict, links, given: dict | None, stack: tuple, memo: dict, cover=None):
         self.doc, self.links, self.stack, self.memo = doc, links, stack, memo
+        self.cover = cover  # 기계 덮음(836-1) — 맨 위 문서 칸 · 부름에 얹음
         self.given = given or {}
         self.vars = {md.var_id(v): v for v in doc.get("변수") or []}
         self.lines = {str(x.get("기호") or ""): x for x in doc.get("식") or []}
@@ -296,7 +298,10 @@ class _Run:
         given = payload.get("입력") or {}
         memo_key = (key, tuple(sorted((k, plain_text(v)) for k, v in given.items())))
         if memo_key not in self.memo:
-            self.memo[memo_key] = calc(doc, self.links, given, (*self.stack, key), self.memo)
+            doc = mcv.cover_doc(doc, given, self.cover)
+            self.memo[memo_key] = calc(
+                doc, self.links, given, (*self.stack, key), self.memo, self.cover
+            )
         got = self.memo[memo_key]
         if not got["셈됨"]:  # 값 없음(결과 빈 입력 · 표 줄 없음) = 빈 값 · 그 밖(표지) = 멈춤
             why = got.get("까닭") or " · ".join(m["글"] for m in got["표지"])
@@ -505,14 +510,19 @@ def rules_of(doc: dict) -> dict:
 
 
 def calc(
-    doc: dict, links, given: dict | None = None, stack: tuple = (), memo: dict | None = None
+    doc: dict,
+    links,
+    given: dict | None = None,
+    stack: tuple = (),
+    memo: dict | None = None,
+    cover: dict | None = None,
 ) -> dict:
     """수식 문서 셈 → {값, 빈값, 줄, 노무비 · 재료비 · 경비 · 계 | 결과,
     묶음, 머리, 단계?, 표지, 셈됨, 끝수}.
-    given = {변수 열쇠: 값}(단가산출 부름이 넘긴 입력) · 예외 없음."""
+    given = {변수 열쇠: 값}(단가산출 부름이 넘긴 입력) · cover = 기계 덮음(없음 = 문서 칸) · 예외 없음."""
     memo = {} if memo is None else memo
     stack = stack or ((str(doc["키"]),) if doc.get("키") else ())  # 제 키 — 저를 부르면 순환
-    run = _Run(doc, links, given, stack, memo)
+    run = _Run(doc, links, given, stack, memo, mcv.cover_of(doc) if cover is None else cover)
     for one in md.check(doc):
         if one["갈래"] in ("기호 꼴", "연결 꼴", "금액 줄", "끝수", "겹침"):
             run.marks.append(one)
diff --git a/resources/master_data/scripts/master_doc_cover.py b/resources/master_data/scripts/master_doc_cover.py
new file mode 100644
index 000000000..b7fe9b260
--- /dev/null
+++ b/resources/master_data/scripts/master_doc_cover.py
@@ -0,0 +1,348 @@
+# -*- coding: utf-8 -*-
+"""기계 덮음 (PLAN 836-1 · 요구 846 · 849 · 850 · 853) — 단가산출 안 기계 내부 값 고침.
+
+자리 = 문서 칸 `기계덮음` {기계 입력 글: {값?: {칸: 값}, 조종원?: [{키, 인}], 잡품?: [{줄? | 키?, 이름?, 수량?, 율}]}}
+    기계 입력 글 = 부름 입력 `기계` 값(따옴표 뗌) — 같은 기계 줄 여럿 = 한 벌 · 원본과 같은 칸 = 없음(`prune`).
+셈 규칙(`cover_doc`) = 계산기(`master_doc_calc.calc`)가 기계 식을 부를 때 그 기계 덮음을 얹은 문서로 셈 —
+    덮음 없음 = 문서 그대로(금액 전후 같음).
+파이썬 · TS 짝 — 짝 = `common_util/common_util_formula_doc_cover.ts` · 거울 시험
+`resources/tester/test_836_1_machine_cover.py`.
+"""
+
+from __future__ import annotations
+
+import copy as cp
+import json
+import re
+from decimal import Decimal
+
+import master_doc as md
+
+COVER = "기계덮음"
+NOT_VALUE = (
+    "조종원",
+    "조종원직종",
+    "잡재료율",
+)  # 값 칸에서 빼는 기계 칸 — 줄(조종원 · 잡품)로 다룸
+HOUR = "Q_시간환산"
+_HOUR_VARS = [
+    {"열쇠": "Q_분자^표", "기호": "Q", "아래": "분자", "위": "표", "이름": "건설기계 조종원 노임 시간 환산 계수.분자",
+     "단위": "", "연결": {"갈래": "표", "표": "CC000336", "조건": {"구분": "'시간환산'"}, "칸": "분자"}},
+    {"열쇠": "Q_분모^표", "기호": "Q", "아래": "분모", "위": "표", "이름": "건설기계 조종원 노임 시간 환산 계수.분모",
+     "단위": "", "연결": {"갈래": "표", "표": "CC000336", "조건": {"구분": "'시간환산'"}, "칸": "분모"}},
+    {"열쇠": "시간환산", "기호": "Q", "아래": "시간환산", "위": "", "이름": "시간환산", "단위": "", "연결": {"갈래": "식"}},
+]  # fmt: skip
+_HOUR_LINE = {"기호": HOUR, "식": "Q_분자^표 ÷ Q_분모^표"}
+MAX_ROWS = 30
+
+
+def _plain(n) -> str:
+    d = Decimal(str(n)).normalize()
+    return format(d, "f")
+
+
+def cover_of(doc) -> dict:
+    got = doc.get(COVER) if isinstance(doc, dict) else None
+    return got if isinstance(got, dict) else {}
+
+
+def machine_key(given) -> str:
+    """부름 입력 → 기계 열쇠(따옴표 뗌) · 기계 입력 없음 = ""."""
+    v = (given or {}).get("기계")
+    if v is None:
+        return ""
+    t = str(v).strip()
+    return t[1:-1] if len(t) >= 2 and t[0] == "'" and t[-1] == "'" else t
+
+
+def _names(text) -> list[str]:
+    if text is None or str(text).strip() == "":
+        return []
+    try:
+        return md.names(md.parse(text))
+    except md.DocError:
+        return []
+
+
+def parts_of(doc: dict) -> dict:
+    """기계 식 짜임 — {fields [{칸, ids}], crew [줄 차례], crew_qty {차례: 기호}, misc, rate, base}."""
+    eq: dict[str, str] = {}
+    for v in doc.get("변수") or []:
+        link = v.get("연결") or {}
+        key = str(link.get("키") or "")
+        if (
+            link.get("갈래") == "요소"
+            and key.startswith("EQ:")
+            and "{S_기계}" in key
+            and link.get("칸")
+        ):
+            eq[md.var_id(v)] = link["칸"]
+    fields: list[dict] = []
+    for id_, col in eq.items():
+        if col in NOT_VALUE:
+            continue
+        at = next((f for f in fields if f["칸"] == col), None)
+        if at:
+            at["ids"].append(id_)
+        else:
+            fields.append({"칸": col, "ids": [id_]})
+    lines = doc.get("금액") or []
+    crew, crew_qty, misc, rate = [], {}, None, None
+    for i, line in enumerate(lines):
+        q = next((n for n in _names(line.get("수량")) if eq.get(n) == "조종원"), None)
+        if line.get("비목") == "노무비" and q:
+            crew.append(i)
+            crew_qty[i] = q
+        p = _names(line.get("단가"))
+        other = [n for n in p if n != "재료비"]
+        if misc is None and line.get("비목") == "재료비" and "재료비" in p and len(other) == 1:
+            misc, rate = i, other[0]
+    base = (
+        []
+        if misc is None
+        else [
+            i
+            for i, x in enumerate(lines)
+            if i < misc and x.get("비목") == "재료비" and not x.get("합밖")
+        ]
+    )
+    return {"fields": fields, "crew": crew, "crew_qty": crew_qty, "misc": misc, "rate": rate, "base": base}  # fmt: skip
+
+
+def _num(v):
+    if isinstance(v, bool) or not isinstance(v, (int, float, Decimal)):
+        return None
+    return v
+
+
+def _fill_key(text: str, vals: dict) -> str:
+    def one(m):
+        v = vals.get(m.group(1))
+        return _plain(v) if _num(v) is not None else str("" if v is None else v)
+
+    return re.sub(r"\{([^{}]+)\}", one, text)
+
+
+def defaults_of(doc: dict, vals: dict) -> dict:
+    """원본(덮음 없음) 기본값 — `vals` = 그 기계로 셈한 원본 답 `값`."""
+    parts = parts_of(doc)
+    lines = doc.get("금액") or []
+    vars_ = {md.var_id(v): v for v in doc.get("변수") or []}
+    values = {}
+    for f in parts["fields"]:
+        v = vals.get(f["ids"][0])
+        if _num(v) is not None or isinstance(v, str):
+            values[f["칸"]] = v
+    crew = []
+    for i in parts["crew"]:
+        n = _num(vals.get(parts["crew_qty"][i]))
+        sym = (_names(lines[i].get("단가")) or [""])[0]
+        key = str(((vars_.get(sym) or {}).get("연결") or {}).get("키") or "")
+        if n and key:
+            crew.append({"키": _fill_key(key, vals), "인": n})
+    r = _num(vals.get(parts["rate"])) if parts["rate"] else None
+    misc = [{"줄": str(lines[i].get("이름") or ""), "율": r} for i in parts["base"]] if r else []
+    return {"값": values, "조종원": crew, "잡품": misc}
+
+
+def _canon(v) -> str:
+    def norm(x):
+        if isinstance(x, dict):
+            return {k: norm(y) for k, y in sorted(x.items()) if y not in (None, "")}
+        if isinstance(x, list):
+            return [norm(y) for y in x]
+        if _num(x) is not None:
+            return float(f"{float(x):.12g}")
+        return x
+
+    return json.dumps(norm(v), ensure_ascii=False, sort_keys=True)
+
+
+def _same(a, b) -> bool:
+    if _num(a) is not None and _num(b) is not None:
+        a, b = float(a), float(b)
+        return abs(a - b) <= 1e-9 * max(1.0, abs(a), abs(b))
+    return str(a) == str(b)
+
+
+def prune(entry: dict, base: dict) -> dict | None:
+    """원본과 같은 칸 · 줄을 뺀 덮음(바꿨다 되돌림 = 안 고침) · 다 빠지면 None."""
+    out: dict = {}
+    vals = {
+        k: v
+        for k, v in (entry.get("값") or {}).items()
+        if v not in (None, "") and not (k in base["값"] and _same(v, base["값"][k]))
+    }
+    if vals:
+        out["값"] = vals
+    for part in ("조종원", "잡품"):
+        if entry.get(part) is not None and _canon(entry[part]) != _canon(base[part]):
+            out[part] = entry[part]
+    return out or None
+
+
+# ── 셈 규칙 ───────────────────────────────────────────────────────────
+def _add_var(doc: dict, sign: str, low: str, name: str, key: str) -> str:
+    have = {md.var_id(v) for v in doc.get("변수") or []} | {
+        str(x.get("기호") or "") for x in doc.get("식") or []
+    }
+    n = 1
+    while md.sym_id(sign, f"{low}{n}") in have:
+        n += 1
+    under = f"{low}{n}"
+    id_ = md.sym_id(sign, under)
+    doc.setdefault("변수", []).append(
+        {"열쇠": id_, "기호": sign, "아래": under, "위": "", "이름": name, "단위": "",
+         "연결": {"갈래": "요소", "키": key}}
+    )  # fmt: skip
+    return id_
+
+
+def _crew_lines(doc: dict, rows: list) -> list[dict]:
+    have = any(md.var_id(v) == HOUR for v in doc.get("변수") or []) or any(
+        x.get("기호") == HOUR for x in doc.get("식") or []
+    )
+    if rows and not have:
+        ids = {md.var_id(v) for v in doc.get("변수") or []}
+        doc.setdefault("변수", []).extend(
+            cp.deepcopy(v) for v in _HOUR_VARS if md.var_id(v) not in ids
+        )
+        doc.setdefault("식", []).append(dict(_HOUR_LINE))
+    return [
+        {"이름": "조종원", "단위": "인", "비목": "노무비", "수량": f"{_plain(r['인'])} × {HOUR}",
+         "단가": _add_var(doc, "w", "조종원", "조종원 노임", r["키"])}
+        for r in rows
+    ]  # fmt: skip
+
+
+def _misc_lines(doc: dict, rows: list, lines: list) -> list[dict]:
+    out = []
+    for r in rows:
+        label = r.get("이름") or ""
+        if r.get("키"):
+            price = _add_var(doc, "P", "잡품", label or r["키"], r["키"])
+            qty = _plain(r["수량"] if r.get("수량") is not None else 1)
+        else:
+            b = next((x for x in lines if str(x.get("이름") or "") == r.get("줄")), None)
+            if not b or not b.get("단가"):
+                continue
+            price = str(b["단가"])
+            qty = _plain(r["수량"]) if r.get("수량") is not None else f"({b.get('수량') or 1})"
+            label = label or str(b.get("이름") or "")
+        out.append(
+            {"이름": "잡품", "규격": label, "단위": "", "비목": "재료비",
+             "수량": f"{qty} × {_plain(r['율'])} ÷ 100", "단가": price}
+        )  # fmt: skip
+    return out
+
+
+def cover_doc(doc: dict, given, cover) -> dict:
+    """기계 식 문서에 그 기계 덮음을 얹음(새 문서) — 덮음 없음 = 그대로(같은 물건)."""
+    key = machine_key(given)
+    entry = (cover or {}).get(key) if key else None
+    if not entry:
+        return doc
+    out = cp.deepcopy(doc)
+    out.pop("쌓기", None)  # 금액 차례가 바뀜 — 기본 차림
+    parts = parts_of(out)
+    values = entry.get("값") or {}
+    for f in parts["fields"]:
+        if f["칸"] in values:
+            for v in out.get("변수") or []:
+                if md.var_id(v) in f["ids"]:
+                    v["연결"] = {"갈래": "숫자", "값": values[f["칸"]]}
+    lines = out.get("금액") or []
+    crew = _crew_lines(out, entry["조종원"]) if entry.get("조종원") is not None else None
+    want = entry.get("잡품")
+    misc = (
+        _misc_lines(out, want, lines)
+        if want is not None and (parts["misc"] is not None or want)
+        else None
+    )
+    gone = set(parts["crew"] if crew is not None else []) | (
+        {parts["misc"]} if misc is not None and parts["misc"] is not None else set()
+    )
+    tail = next((i for i, x in enumerate(lines) if x.get("비목") == "경비"), len(lines))
+    crew_at = parts["crew"][0] if parts["crew"] else tail
+    misc_at = parts["misc"] if parts["misc"] is not None else tail
+    new = []
+    for i in range(len(lines) + 1):
+        if crew is not None and i == crew_at:
+            new += crew
+        if misc is not None and i == misc_at:
+            new += misc
+        if i < len(lines) and i not in gone:
+            new.append(lines[i])
+    out["금액"] = new
+    return out
+
+
+# ── 서버 검사 · 정리 ──────────────────────────────────────────────────
+def _nonneg(v, where: str):
+    if isinstance(v, bool) or not isinstance(v, (int, float, Decimal)) or v < 0:
+        raise ValueError(f"{where} — 0 이상 수")
+    return v
+
+
+def clean(raw) -> dict:
+    """몸 검사 — 틀리면 ValueError(까닭) · 빈 칸 · 빈 기계 = 뺌."""
+    if raw is None:
+        return {}
+    if not isinstance(raw, dict):
+        raise ValueError(f"{COVER} — 묶음 아님")
+    out: dict = {}
+    for key, entry in raw.items():
+        if not isinstance(entry, dict):
+            raise ValueError(f"{COVER} 「{key}」 — 묶음 아님")
+        one: dict = {}
+        values = entry.get("값")
+        if values is not None:
+            if not isinstance(values, dict):
+                raise ValueError(f"{COVER} 「{key}」 값 — 묶음 아님")
+            got = {}
+            for col, v in values.items():
+                if v in (None, ""):
+                    continue
+                if col in NOT_VALUE:
+                    raise ValueError(f"{COVER} 「{key}」 값 「{col}」 — 줄로 고침")
+                got[col] = v.strip() if isinstance(v, str) else _nonneg(v, f"「{key}」 {col}")
+            if got:
+                one["값"] = got
+        for part, need in (("조종원", ("키", "인")), ("잡품", ("율",))):
+            rows = entry.get(part)
+            if rows is None:
+                continue
+            if not isinstance(rows, list) or len(rows) > MAX_ROWS:
+                raise ValueError(f"{COVER} 「{key}」 {part} — 목록({MAX_ROWS} 줄까지)")
+            for r in rows:
+                if not isinstance(r, dict) or any(r.get(k) in (None, "") for k in need):
+                    raise ValueError(f"{COVER} 「{key}」 {part} 줄 — {' · '.join(need)} 필요")
+                for k in ("인", "율", "수량"):
+                    if r.get(k) is not None:
+                        _nonneg(r[k], f"「{key}」 {part} {k}")
+                if part == "잡품" and not (r.get("줄") or r.get("키")):
+                    raise ValueError(f"{COVER} 「{key}」 잡품 줄 — 재료(키) 또는 줄 필요")
+            one[part] = rows
+        if one:
+            out[str(key)] = one
+    return out
+
+
+def prune_doc(doc: dict, links) -> dict:
+    """서버 정리 — 덮음을 검사하고 원본과 같은 칸 · 줄 · 기계를 뺀 문서(새 문서 · 덮음 없음 = 그대로).
+    원본 = 덮음 뺀 문서 셈의 부름 메모(그 기계 식 · 입력 · 원본 답)."""
+    import master_doc_calc as mc
+
+    cover = clean(doc.get(COVER))
+    rest = {k: v for k, v in doc.items() if k != COVER}
+    if not cover:
+        return rest
+    memo: dict = {}
+    mc.calc(rest, links, None, (), memo)
+    kept: dict = {}  # 문서가 안 부르는 기계 덮음 = 뺌
+    for (key, given), ans in memo.items():
+        m = machine_key(dict(given))
+        sub = links.doc(key) if m in cover and m not in kept else None
+        if sub and (one := prune(cover[m], defaults_of(sub, ans.get("값") or {}))):
+            kept[m] = one
+    return {**rest, COVER: kept} if kept else rest
diff --git a/resources/tester/helper_836_1_machine_cover.cjs b/resources/tester/helper_836_1_machine_cover.cjs
new file mode 100644
index 000000000..3b4c13d28
--- /dev/null
+++ b/resources/tester/helper_836_1_machine_cover.cjs
@@ -0,0 +1,63 @@
+/* 836-1 기계 덮음 거울 헬퍼 — common_util_formula_doc_cover.ts · calc 를 그 자리에서 트랜스파일해 Node 로 돌림.
+ * stdin = {문서들: {키: 문서}, 대상: [{문서, 덮음?}], 기록: {열쇠: {값 | 빈 | 끊김}}, 짜임: [{문서, 입력, 덮음, 값}]}
+ * stdout = {답: [calcDoc 답], 짜임: [{얹음: coverDoc, 기본: defaultsOf, 정리: prune}]}
+ * 기록 열쇠 = 갈래 + "|" + 값 글(파이썬 `_canon` 과 같은 꼴 · helper_802_1 과 같음). */
+const fs = require("fs");
+const path = require("path");
+const ts = require(path.join(__dirname, "..", "..", "config", "node_modules", "typescript"));
+
+const cache = new Map();
+function load(at) {
+  if (cache.has(at)) return cache.get(at);
+  const js = ts.transpileModule(fs.readFileSync(at, "utf8"), {
+    compilerOptions: { module: ts.ModuleKind.CommonJS, target: ts.ScriptTarget.ES2020 },
+  }).outputText;
+  const box = { exports: {} };
+  cache.set(at, box.exports);
+  const need = (p) =>
+    p.startsWith(".") ? load(path.resolve(path.dirname(at), `${p}.ts`)) : require(p);
+  new Function("exports", "module", "require", js)(box.exports, box, need);
+  return box.exports;
+}
+const root = path.join(__dirname, "..", "..", "common_util");
+const calc = load(path.join(root, "common_util_formula_doc_calc.ts"));
+const cover = load(path.join(root, "common_util_formula_doc_cover.ts"));
+
+function canon(v) {
+  if (typeof v === "number") return calc.plainText(v);
+  if (Array.isArray(v)) return v.map(canon);
+  if (v && typeof v === "object") {
+    const out = {};
+    for (const k of Object.keys(v).sort()) out[k] = canon(v[k]);
+    return out;
+  }
+  return v;
+}
+const input = JSON.parse(fs.readFileSync(0, "utf8"));
+const record = input.기록 || {};
+function answer(kind, p) {
+  const k = `${kind}|${JSON.stringify(canon(p))}`;
+  if (!(k in record)) throw new calc.Broken(`기록 없음 ${k}`);
+  const got = record[k];
+  if ("빈" in got) throw new calc.Gap(got.빈);
+  if ("끊김" in got) throw new calc.Broken(got.끊김);
+  return got.값;
+}
+const links = {
+  element: (p) => answer("요소", p),
+  table: (p) => answer("표", p),
+  doc: (key) => (input.문서들 || {})[key] || null,
+};
+const out = { 답: [], 짜임: [] };
+for (const one of input.대상 || [])
+  out.답.push(calc.calcDoc(one.덮음 ? { ...one.문서, 기계덮음: one.덮음 } : one.문서, links));
+for (const one of input.짜임 || []) {
+  const base = cover.defaultsOf(one.문서, one.값);
+  const key = cover.machineKey(one.입력);
+  out.짜임.push({
+    얹음: cover.coverDoc(one.문서, one.입력, one.덮음),
+    기본: base,
+    정리: one.덮음[key] ? cover.prune(one.덮음[key], base) : null,
+  });
+}
+process.stdout.write(JSON.stringify(out));
diff --git a/resources/tester/test_836_1_machine_cover.py b/resources/tester/test_836_1_machine_cover.py
new file mode 100644
index 000000000..55941ff82
--- /dev/null
+++ b/resources/tester/test_836_1_machine_cover.py
@@ -0,0 +1,336 @@
+"""836-1 기계 덮음 — 셈 규칙 · 기본값 · 정리 · 몸 검사 · 거울(파이썬 ↔ TS) 지킴 시험.
+
+짝 = `resources/master_data/scripts/master_doc_cover.py` ↔ `common_util/common_util_formula_doc_cover.ts`
+(계산기 부름 자리 = `master_doc_calc` ↔ `common_util_formula_doc_calc.ts`).
+① 덮음 없음 = 문서 그대로(같은 물건 · 같은 금액) · 남의 기계 덮음 = 안 얹음.
+② 굴착기(무한궤도) 1.0㎥(0201-0100 · GC000267) — 값 · 조종원 · 잡품 덮음 = 손셈(M01 값).
+③ 조종원 없는 식에 조종원 더함(시간환산 표 더함) · 잡품 없는 식에 잡품 더함 · 연료 + 전력 식 기본 잡품 둘.
+④ 정리 — 원본과 같으면 지움 · 안 부르는 기계 지움 · 몸 검사 틀림.
+⑤ 거울 — 같은 연결 값으로 파이썬 · TS 답 · 얹은 문서 · 기본값 · 정리가 같음.
+"""
+
+import importlib
+import json
+import os
+import subprocess
+from decimal import Decimal as D
+
+import pytest
+
+from M01_MasterData import M01_MasterData_Store as m01  # scripts 길을 둠
+
+mc = importlib.import_module("master_doc_calc")
+ml = importlib.import_module("master_doc_link")
+mcv = importlib.import_module("master_doc_cover")
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+COSTS = ("노무비", "재료비", "경비", "계")
+NO = "0201-0100"  # 굴착기(무한궤도) 1.0㎥ — 조사 846 1 장 견본
+
+
+@pytest.fixture(scope="module")
+def links():
+    _, whole = m01.loaded()
+    return ml.Links(whole)
+
+
+def _one(logic: str, no: str, cover: dict | None = None) -> dict:
+    """기계 한 줄 문서(1 hr) — 덮음 = 문서 칸."""
+    var = {"열쇠": "P_기계", "기호": "P", "아래": "기계", "위": "", "이름": "기계", "단위": "",
+           "연결": {"갈래": "단가산출", "키": logic, "입력": {"기계": f"'{no}'"}}}  # fmt: skip
+    line = {"이름": "기계", "단위": "hr", "비목": "묶음", "수량": "1", "단가": "P_기계"}
+    doc = {"꼴": "수식문서", "판": 1, "키": "_t", "이름": "t", "결과단위": "원",
+           "변수": [var], "식": [], "금액": [line]}  # fmt: skip
+    return {**doc, mcv.COVER: cover} if cover else doc
+
+
+def _money(ans):
+    return {k: ans.get(k) for k in COSTS}
+
+
+def _first(links, logic: str) -> str:
+    var = next(v for v in links.doc(logic)["변수"] if v.get("열쇠") == "기계")
+    return str(var["연결"]["목록"][0])
+
+
+def _orig(links, logic: str, no: str) -> dict:
+    memo: dict = {}
+    mc.calc(_one(logic, no), links, None, (), memo)
+    return next(a for (k, _), a in memo.items() if k == logic)
+
+
+# ── ① 덮음 없음 ────────────────────────────────────────────────────────
+def test_덮음_없음_같은_물건_같은_금액(links):
+    doc = links.doc("GC000267")
+    assert mcv.cover_doc(doc, {"기계": NO}, {}) is doc
+    assert mcv.cover_doc(doc, {"기계": NO}, {"0201-0120": {"값": {"가격": 1}}}) is doc
+    assert mcv.cover_doc(doc, {}, {NO: {"값": {"가격": 1}}}) is doc
+    base = mc.calc(_one("GC000267", NO), links)
+    other = mc.calc(_one("GC000267", NO, {"0201-0120": {"값": {"가격": 1}}}), links)
+    assert _money(base) == _money(other)
+    assert base["계"] == D(108958) or base["셈됨"]  # M01 값이 바뀌면 금액은 달라도 됨(값 대조는 ②)
+
+
+# ── ② 손셈 ────────────────────────────────────────────────────────────
+def _cut1(x):
+    return D(str(x)).quantize(D("0.1"), rounding="ROUND_DOWN")
+
+
+def test_굴착기_덮음_손셈(links):
+    v = _orig(links, "GC000267", NO)["값"]
+    price, fuel, oil = v["P_기계"], v["P_기계주연료"], v["P_자동차용경유"]
+    wage, rate = v["w_기계운전사"], v["r_기계잡재료"]
+    k = (v["k_기계상각비"] + v["k_기계정비비"]) * (1 + v["r_가산"] / 100) + v["k_기계관리비"]
+
+    def loss(p):
+        return (D(p) * 1000 * k / D(10) ** 7).to_integral_value(rounding="ROUND_DOWN")
+
+    def total(labor, mats, exp):
+        return {"노무비": int(labor), "재료비": int(mats), "경비": int(exp)}
+
+    fuel_amt = _cut1(fuel * oil)
+    crew1 = _cut1(D(1) / 8 * wage)
+    misc = _cut1(fuel_amt * rate / 100)
+    want = total(crew1, fuel_amt + misc, loss(price))
+    got = mc.calc(_one("GC000267", NO), links)
+    assert {c: int(got[c]) for c in ("노무비", "재료비", "경비")} == want
+
+    def run(cover):
+        a = mc.calc(_one("GC000267", NO, {NO: cover}), links)
+        assert a["셈됨"], a["표지"]
+        return {c: int(a[c]) for c in ("노무비", "재료비", "경비")}
+
+    assert run({"값": {"가격": 150000}}) == total(crew1, fuel_amt + misc, loss(150000))
+    f20 = _cut1(20 * oil)
+    assert run({"값": {"주연료": 20}}) == total(crew1, f20 + _cut1(f20 * rate / 100), loss(price))
+    assert run({"조종원": [{"키": "LB:1048", "인": 2}]}) == total(
+        _cut1(D(2) / 8 * wage), fuel_amt + misc, loss(price)
+    )
+    assert run({"조종원": []}) == total(0, fuel_amt + misc, loss(price))
+    assert run({"잡품": [{"줄": "주연료", "율": 30}]}) == total(
+        crew1, fuel_amt + _cut1(fuel * oil * 30 / 100), loss(price)
+    )
+    assert run({"잡품": []}) == total(crew1, fuel_amt, loss(price))
+    # 다른 직종 · 사람 둘 = 두 줄
+    two = run({"조종원": [{"키": "LB:1048", "인": 1}, {"키": "LB:1002", "인": 1}]})
+    labor = mc.calc(_one("GC000267", NO, {NO: {"조종원": [{"키": "LB:1002", "인": 1}]}}), links)
+    assert two["노무비"] == int(crew1) + int(labor["노무비"])
+
+
+# ── ③ 줄 더함 ─────────────────────────────────────────────────────────
+def test_조종원_없는_식에_조종원_잡품_없는_식에_잡품(links):
+    no = _first(links, "GC000272")
+    base = mc.calc(_one("GC000272", no), links)
+    got = mc.calc(_one("GC000272", no, {no: {"조종원": [{"키": "LB:1048", "인": 1}]}}), links)
+    assert got["셈됨"], got["표지"]
+    assert got["노무비"] > 0 and got["재료비"] == base["재료비"] and got["경비"] == base["경비"]
+    no3 = _first(links, "GC000273")
+    base3 = mc.calc(_one("GC000273", no3), links)
+    got3 = mc.calc(
+        _one("GC000273", no3, {no3: {"잡품": [{"키": "LB:1048", "수량": 1, "율": 10}]}}), links
+    )
+    assert got3["셈됨"] and got3["재료비"] > base3["재료비"] == 0
+
+
+def test_연료_전력_식_기본_잡품_둘(links):
+    doc = links.doc("GC001200")
+    parts = mcv.parts_of(doc)
+    assert parts["misc"] is not None and len(parts["base"]) == 2
+
+
+# ── ④ 정리 · 검사 ─────────────────────────────────────────────────────
+def test_원본과_같으면_지움_안_부르는_기계_지움(links):
+    v = _orig(links, "GC000267", NO)["값"]
+    same = {NO: {"값": {"가격": v["P_기계"]}, "조종원": [{"키": "LB:1048", "인": 1}],
+                 "잡품": [{"줄": "주연료", "율": v["r_기계잡재료"]}]}}  # fmt: skip
+    assert mcv.COVER not in mcv.prune_doc(_one("GC000267", NO, same), links)
+    mixed = {NO: {"값": {"가격": v["P_기계"], "주연료": 20}}, "9999-9999": {"값": {"가격": 1}}}
+    got = mcv.prune_doc(_one("GC000267", NO, mixed), links)[mcv.COVER]
+    assert got == {NO: {"값": {"주연료": 20}}}
+
+
+@pytest.mark.parametrize(
+    "bad",
+    [
+        [],
+        {NO: 1},
+        {NO: {"값": {"가격": -1}}},
+        {NO: {"값": {"조종원": 2}}},
+        {NO: {"조종원": [{"키": "", "인": 1}]}},
+        {NO: {"조종원": [{"키": "LB:1048", "인": -1}]}},
+        {NO: {"잡품": [{"율": 10}]}},
+        {NO: {"잡품": [{"줄": "주연료", "율": "x"}]}},
+    ],
+)
+def test_몸_검사_틀림(bad):
+    with pytest.raises(ValueError):
+        mcv.clean(bad)
+
+
+def test_몸_검사_빈_칸_뺌():
+    assert mcv.clean({NO: {"값": {"가격": ""}}}) == {}
+    assert mcv.clean({NO: {"값": {"가격": 0}}}) == {NO: {"값": {"가격": 0}}}
+
+
+# ── ⑤ 거울 ────────────────────────────────────────────────────────────
+def _canon(v):
+    if isinstance(v, (D, int, float)) and not isinstance(v, bool):
+        return mc.plain_text(D(str(v)))
+    if isinstance(v, list):
+        return [_canon(x) for x in v]
+    if isinstance(v, dict):
+        return {k: _canon(v[k]) for k in sorted(v)}
+    return v
+
+
+class Rec:
+    def __init__(self, links):
+        self.links, self.log = links, {}
+
+    def _keep(self, kind, p, fn):
+        key = f"{kind}|{json.dumps(_canon(p), ensure_ascii=False, separators=(',', ':'))}"
+        try:
+            got = fn(p)
+        except mc.Gap as e:
+            self.log[key] = {"빈": str(e)}
+            raise
+        except mc.Broken as e:
+            self.log[key] = {"끊김": str(e)}
+            raise
+        self.log[key] = {"값": got}
+        return got
+
+    def element(self, p):
+        return self._keep("요소", p, self.links.element)
+
+    def table(self, p):
+        return self._keep("표", p, self.links.table)
+
+    def doc(self, key):
+        return self.links.doc(key)
+
+
+def _same(a, b, where=""):
+    if isinstance(a, dict):
+        assert isinstance(b, dict) and set(a) == set(b), (where, sorted(a), sorted(b or {}))
+        for k in a:
+            _same(a[k], b[k], f"{where}.{k}")
+    elif isinstance(a, list):
+        assert isinstance(b, list) and len(a) == len(b), where
+        for i, (x, y) in enumerate(zip(a, b)):
+            _same(x, y, f"{where}[{i}]")
+    elif isinstance(a, (D, int, float)) and not isinstance(a, bool):
+        assert isinstance(b, (int, float)) and not isinstance(b, bool), (where, a, b)
+        assert float(a) == pytest.approx(b, rel=1e-9, abs=1e-9), (where, a, b)
+    else:
+        assert a == b, (where, a, b)
+
+
+COVERS = [
+    None,
+    {"값": {"가격": 150000, "주연료종류": "휘발유"}},
+    {"조종원": [{"키": "LB:1048", "인": 2}, {"키": "LB:1002", "인": 0.5}]},
+    {"조종원": []},
+    {"잡품": [{"줄": "주연료", "율": 30}, {"키": "LB:1048", "이름": "시험", "수량": 2, "율": 5}]},
+    {"잡품": [{"줄": "주연료", "수량": 10, "율": 22}]},
+]
+
+
+def test_거울_파이썬_TS_같은_답(links):
+    rec = Rec(links)
+    picks = [("GC000267", NO)] + [
+        (k, _first(links, k))
+        for k in ("GC000272", "GC000273", "GC000275", "GC000276", "GC001196", "GC001197")
+    ]
+    cases, want, shapes, shape_want = [], [], [], []
+    for logic, no in picks:
+        orig = _orig(Rec(links), logic, no)  # 기록에 안 섞임(원본 셈은 아래에서 다시)
+        for one in COVERS:
+            cover = {no: one} if one else None
+            doc = _one(logic, no)
+            cases.append({"문서": doc, "덮음": cover})
+            want.append(mc.calc({**doc, mcv.COVER: cover} if cover else doc, rec))
+            if cover:
+                base = mcv.defaults_of(links.doc(logic), orig["값"])
+                shapes.append({"문서": links.doc(logic), "입력": {"기계": no}, "덮음": cover,
+                               "값": orig["값"]})  # fmt: skip
+                shape_want.append({"얹음": mcv.cover_doc(links.doc(logic), {"기계": no}, cover),
+                                   "기본": base, "정리": mcv.prune(cover[no], base)})  # fmt: skip
+    docs = {k: links.doc(k) for k, _ in picks}
+    payload = {"문서들": docs, "대상": cases, "기록": rec.log, "짜임": shapes}
+    proc = subprocess.run(
+        ["node", os.path.join(HERE, "helper_836_1_machine_cover.cjs")],
+        input=json.dumps(ml._norm(payload), ensure_ascii=False),
+        capture_output=True,
+        text=True,
+        encoding="utf-8",
+        check=True,
+    )
+    got = json.loads(proc.stdout)
+    for i, (a, b) in enumerate(zip(want, got["답"])):
+        _same(ml._norm(_money(a)), _money(b), f"답{i}")
+        _same(ml._norm(a["값"]), b["값"], f"값{i}")
+    assert len(got["짜임"]) == len(shape_want)
+    for i, (a, b) in enumerate(zip(shape_want, got["짜임"])):
+        _same(ml._norm(a), b, f"짜임{i}")
+
+
+# ── ⑥ 서버 저장 길(임시 층 · 수식 길) ────────────────────────────────────
+@pytest.fixture
+def world(tmp_path, monkeypatch):
+    from resources.tester.test_m02_labor_ref import world as make
+
+    return make.__wrapped__(tmp_path, monkeypatch)
+
+
+def test_저장_다시_열기_되돌리면_덮음_없음(world):
+    import copy as cp
+
+    from M02_MasterTemplete import M02_Doc_Sk_Path as path
+    from M02_MasterTemplete import M02_Labor_Ref as refs
+    from M02_MasterTemplete import M02_MasterTemplete_Store as store
+
+    me = world["personal"]
+
+    def at(fn, *args):
+        with store.at(me):
+            return fn(*args)
+
+    key = at(
+        lambda: refs.create("sangeun", {"이름": "sub3임시 덮음", "단위": "시간", "더한줄": []})
+    )
+    key = key["이름"]
+    got = at(path.read, key)
+    doc = cp.deepcopy(got["문서"])
+    link = {"갈래": "단가산출", "키": "GC000267", "입력": {"기계": f"'{NO}'"}}
+    for s in ("기계", "기계둘"):
+        doc.setdefault("변수", []).append(
+            {"기호": "P", "아래": s, "위": "", "이름": s, "단위": "", "연결": link}
+        )
+        doc.setdefault("금액", []).append(
+            {"이름": s, "단위": "hr", "비목": "묶음", "수량": "1", "단가": f"P_{s}"}
+        )
+    at(path.save, key, {"문서": doc, "판": got["판"]})
+    base = at(path.read, key)
+    was = base["셈"]["계"]
+    one = base["셈"]["줄"][0]["금액"]
+    doc = cp.deepcopy(base["문서"])
+    doc[mcv.COVER] = {NO: {"값": {"가격": 150000}}, "9999-9999": {"값": {"가격": 1}}}
+    after = at(path.save, key, {"문서": doc, "판": base["판"]})
+    assert after["문서"][mcv.COVER] == {NO: {"값": {"가격": 150000}}}  # 안 부르는 기계 = 뺌
+    lines = after["셈"]["줄"]
+    assert lines[0]["금액"] == lines[1]["금액"] > one  # 같은 기계 두 줄 = 같이 바뀜
+    again = at(path.read, key)
+    assert again["문서"][mcv.COVER] == {NO: {"값": {"가격": 150000}}}
+    assert again["셈"]["계"] == after["셈"]["계"] > was
+    v = _orig(ml.Links(m01.loaded()[1]), "GC000267", NO)["값"]
+    doc = cp.deepcopy(again["문서"])
+    doc[mcv.COVER] = {NO: {"값": {"가격": v["P_기계"]}}}  # 되돌림 = 원본 값
+    back = at(path.save, key, {"문서": doc, "판": again["판"]})
+    assert mcv.COVER not in back["문서"] and back["셈"]["계"] == was
+    with store.at(me):
+        file = store.read("sangeun", key)["문서"]
+    assert mcv.COVER not in file["수식"]["문서"]
+    doc[mcv.COVER] = {NO: {"값": {"가격": -5}}}
+    with pytest.raises(store.StoreError):
+        at(path.save, key, {"문서": doc, "판": back["판"]})