Stages 3a and 3b landed (#167, #170). Re-scouting Stage 4 against main
@ d400f30 produced six findings that change the plan and three that
confirm it. The pmacs-side facts were verified in a worktree at that
commit; the upstream facts by reading leanprover/vscode-lean4 @ 17d1d08.
The split: Stage 4's risk column read "refactors pair.lua's provenance
read" — every language's auto-pairing — for a stage the prose called the
Lean input method, which is exactly the rule §4 states and exactly what
round 4 found for Stage 3. Rev 5 had noticed the shape and answered it
with a commit boundary; a commit boundary is not a review boundary.
Stage 4a is now the typed-edit consumer chain (substrate, no Lean) and
4b the input method.
Rev 5's expansion semantics were wrong in three ways. Resolution is the
shortest key having the input as a prefix (\al yields ∀ from `all`, not
`alpha`); there is no terminator list at all ('+ ' is a key, so space
extends after \+; '\' is a key, so \\ yields \); and an unmatchable tail
is appended rather than dropped (\alp7 yields α7).
Three further findings. There is no cursor-motion hook, so acceptance 43
as written was not buildable and abandonment is lazy. dispatch_key is
only half of 4b's production path — \ and the letters are not excluded
from the optimistic classifier, and that producer is crdt-gated, so a
crdt-gated integration test is dark in CI and dark in the gate list. And
the whole expansion has cross-peer-degraded undo, a wider bite than
Q#LN6's three bracket pairs; set_round_trip_input would fix it and is
rejected with reasons.
New decisions Q#LN21 (undo degradation) and Q#LN22 (the state machine);
Q#LN10 and Q#LN11 rewritten; §2.11 records the upstream algorithm; §9.1
states the coherence impact for both stages. Acceptance keeps its
existing numbers and adds letter suffixes on both sides of the split.
Citation sweep per COHERENCE §25: five live citations moved in the 50
commits since rev 5.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011LFvC4FQtux4y32KuevZ7B
Levi Neuwirth
3b54c78494