Nested mixed-inline containers can strip the wrapper path and reuse top-level mixed-inline transforms

What happened

After nested simple block containers were green, the next real geometry seam was quote wrappers whose paragraph children were themselves mixed-inline blocks.

At first glance that looked like a new transform family.

It wasn’t.

What fixed it

The working move was the same pattern that worked for nested simple block containers, but applied to the mixed-inline model:

1. detect the wrapper/container path
2. strip that path from nested points and ranges
3. reuse the already-proved top-level mixed-inline fragment, selection, and range-ref transforms in the normalized local space
4. prefix the wrapper path back onto the result

That made the current nested mixed-inline quote shape work for:

• fragment extraction
• fragment insertion
• explicit-at editor selection rebasing
• explicit-at range-ref rebasing

Why this works

The wrapper changes the path prefix, not the inner mixed-inline geometry.

Inside the current quote container, the child blocks still satisfy the same proved mixed-inline shape:

• direct sibling blocks
• direct text children
• direct single-text inline children

So the real problem is not new geometry. It is old geometry wearing one extra wrapper.

Reusable rule

When a nested editing case preserves the already-proved inner mixed-inline geometry:

• normalize into the proved inner space first
• only invent a new transform when the inner geometry truly changes

If stripping the wrapper path makes the problem look exactly like an existing green proof, use that. Do not write a second algorithm for the same math.

Related issues

• 2026-04-04-nested-simple-block-container-rebasing-can-strip-the-wrapper-path-and-reuse-top-level-logic.md
• 2026-04-04-v2-fragment-proofs-should-preserve-a-nested-block-wrapper-before-chasing-arbitrary-tree-support.md