# LDC-E5301 — Amendment touches a protected fragment

## What it means

An entrenchment marks a fragment as untouchable: within its time window,
no amendment may change the protected text, no matter how correctly the
amendment follows the procedure. The compiler checks every operation of
every revision edge against the active entrenchments before applying
anything. When an operation would rewrite a protected fragment, the whole
edge is refused at that operation.

## Example

```law
language "law.core" version "0.2";
package demo.diagnostics version "0.1.0";
namespace "urn:law:demo:diagnostics";

source ORDER { kind ministerial_order; }
edition ED_2025 of ORDER { language ru; officiality official; }
edition ED_2026 of ORDER { language ru; officiality official; }
fragment F_OLD in ED_2025 { kind article; locator "article/5";
  text ru official """старая редакция"""; }
fragment F_NEW in ED_2026 { kind article; locator "article/5";
  text ru official """новая редакция"""; }
entrenchment PROT { source ORDER; locator "article/5"; window [@2025-01-01, infinity); }
revision LAW_1 {
  previous ED_2025;
  next ED_2026;
  relation amends;
  op replace { locator "article/5"; language ru; text """новая редакция"""; }
}
```

## Fix

```law
language "law.core" version "0.2";
package demo.diagnostics version "0.1.0";
namespace "urn:law:demo:diagnostics";

source ORDER { kind ministerial_order; }
edition ED_2025 of ORDER { language ru; officiality official; }
edition ED_2026 of ORDER { language ru; officiality official; }
fragment F_OLD in ED_2025 { kind article; locator "article/5";
  text ru official """старая редакция"""; }
fragment F_NEW in ED_2026 { kind article; locator "article/5";
  text ru official """новая редакция"""; }
revision LAW_1 {
  previous ED_2025;
  next ED_2026;
  relation amends;
  op replace { locator "article/5"; language ru; text """новая редакция"""; }
}
```

## Engine message

The engine reports this in its own wording:

```text
example.law:17:3: error LDC-E5301: edge "LAW_1": operation #0 modifies protected fragment article/5 (ru) from article/5; the amendment is unlawful regardless of procedure compliance (§32.3)
```

## Related

- [Prohibitions](/constructs/prohibition/) — what can never be done, however regular the path.
- [Time](/constructs/time/) — how protection windows bound an amendment.