rose-ash/plans/agent-briefings/maude-loop.md

# maude-on-sx loop agent (single agent, queue-driven)

Role: iterates `plans/maude-on-sx.md` forever. **Rewriting as the only primitive** —
equational logic + term rewriting modulo theories (assoc/comm/id). The chisel is
*the reduction step*: Maude asks "what is one step of computation?" and answers
with rewrite-modulo-equations, more general than the CEK transition. One feature
per commit.

```
description: maude-on-sx queue loop
subagent_type: general-purpose
run_in_background: true
isolation: worktree
```

## Prerequisites — check before starting

1. **lib-guest lex + pratt present** — the `fmod`/`endfm` parser consumes
   `lib/guest/lex.sx` + `lib/guest/pratt.sx`.

**Pre-flight:**
```
ls /root/rose-ash/lib/guest/lex.sx /root/rose-ash/lib/guest/pratt.sx
```
If missing, stop and record a Blockers entry. (Maude needs no special core
primitive — it builds its own term/rewrite machinery in SX.)

## Prompt

You are the sole background agent working `/root/rose-ash/plans/maude-on-sx.md`,
in an isolated git worktree on branch `loops/maude`, forever, one commit per
feature. Push to `origin/loops/maude` after every commit. Never touch `main` or
`architecture`.

## Restart baseline — check before iterating

1. Read `plans/maude-on-sx.md` — Roadmap + Progress log + Blockers.
2. Run the pre-flight; record gaps in Blockers.
3. `ls lib/maude/` — pick up from the most advanced file. No dir → Phase 1.
4. If `lib/maude/tests/*.sx` exist, run them via the epoch protocol against
   `sx_server.exe`. Green before new work.

## The queue

Phase order per `plans/maude-on-sx.md`:

- **Phase 1** — parser + signatures (`fmod`/`endfm`, sorts + subsorts, op decls,
  equations; overloading by arity+sort)
- **Phase 2** — syntactic equational reduction (apply eqs left-to-right to a fixpoint;
  strict pattern match)
- **Phase 3** — **equational matching modulo assoc/comm/id** (the chisel: flatten AC
  operators, match across permutations/multisets; return *all* matches)
- **Phase 4** — conditional equations (`ceq L = R if Cond`)
- **Phase 5** — system modules + rewrite rules (`rl … => …`, asymmetric, fairness)
- **Phase 6** — strategy language (`;`, `|`, `*`, fixed-point; named strategies)
- **Phase 7** — reflection (META-LEVEL: terms-as-data, meta-interpretation)
- **Phase 8** — propose `lib/guest/rewriting/` extraction (wait for a 2nd consumer)

Within a phase, pick the checkbox with the best tests-per-effort ratio.
Every iteration: implement → test → commit → tick `[ ]` → Progress log → push → next.

## Chisel discipline — the reduction step

The payoff is **Phase 3's AC matching**: matching modulo associativity/commutativity/
identity is genuinely harder than the substitution the CEK does, and it's where
Maude's "reduction step" diverges from SX's. Implement it as a term-rewriting
engine *in SX* (terms are SX data; matching returns substitution sets). Do NOT try
to bend the CEK into a rewriter — Maude runs *on* the CEK as an interpreter, it does
not replace it. Note for the integrator: the AC-matching + normal-form engine is the
prime candidate to feed an eventual `artdag-on-sx` effect-pipeline optimizer
(`plans/artdag-on-sx.md`) — keep it cleanly separable (Phase 8).

## Ground rules (hard)

- **Scope:** only `lib/maude/**` and `plans/maude-on-sx.md`. Do **not** edit
  `spec/`, `hosts/`, `shared/`, `lib/guest/**` (read-only), or other `lib/<lang>/`.
- **Consume `lib/guest/`** (lex, pratt). The rewrite engine itself is yours.
- **Don't patch the substrate.** Maude is an interpreter over SX terms; substrate
  gaps → failing test + Blockers entry, never a `spec/` patch.
- **NEVER call `sx_build`** (600s watchdog). Broken binary → Blockers, stop.
- **SX files:** `sx-tree` MCP tools ONLY; `sx_validate` after every edit; `file:` not
  `path:`. Never `Edit`/`Read`/`Write` on `.sx`.
- **Worktree:** commit, then push `origin/loops/maude`. Never `main`/`architecture`.
- **Commits:** one feature per commit (`maude: AC matching for assoc-comm ops + 6 tests`).
- **Plan file:** Progress log + tick boxes every commit.
- **Blocked 2 iterations → Blockers, move on.**

## Maude-specific gotchas

- **Equations vs rules.** `eq`/`ceq` are *equational* (`=`, applied to a fixpoint to
  normalise, confluent-by-intent); `rl` are *transitions* (`=>`, asymmetric,
  possibly nondeterministic). Don't apply rules during equational reduction.
- **AC operators flatten.** `_+_` assoc means `a + (b + c)` and `(a + b) + c` are the
  same term — normalise to a flat sequence/multiset before matching, and match
  across orderings for `comm`.
- **Matching returns a set of substitutions, not one.** AC matching is multi-valued;
  Phase 3 must yield all matches and let the caller drive (rule application picks).
- **Identity is a rewrite, not a special case.** `id: e` for `_*_` means `X * e ≡ X`
  in both directions — handle as an equation in the AC matcher, carefully (avoid
  infinite insertion of identities).
- **Strategies make the same rules mean different things** — Phase 6 evaluation
  result depends on strategy; keep rule set and strategy orthogonal.

## General gotchas (all loops)

- SX `do` = R7RS iteration; use `begin` for multi-expr sequences.
- `cond`/`when`/`let` clauses evaluate only the last expr — wrap multiples in `begin`.
- `let` is parallel — nest `let`s when one binding references an earlier one.
- `env-bind!` creates a binding; `env-set!` mutates an existing one.
- Namespace-prefix guest helpers (`mau/…`).
- Shell heredoc `||` gets eaten — escape or use `case`.

## Style

- No comments in `.sx` unless non-obvious. No new planning docs — update the plan.
- Short, factual commit messages. One feature per iteration. Commit. Log. Push. Next.

Go. Run the pre-flight. If lib-guest is missing, stop and report. Otherwise read
the plan, find the first unchecked `[ ]`, implement it.