mpa-atlas

📄 Published paper: Metastable Propositional Algebra: The finite-drive deformation of Boolean structure — the public-facing prose-and-prior-art version, frozen at publication as framework/archive/mpav1_unabridged.md. Open access (CC-BY-4.0): DOI 10.5281/zenodo.20357550. The published mpav1_* snapshot is the citable artifact; the live operational source of truth has since been re-modularized into the framework/mpa_* set below (character_engine.md claims + character_receipts_engine.md derivations).

⚠ Read CLAUDE.md before touching any RFC. This repo operates under thin-RFC discipline — exchange surfaces are written at gross-underengineering resolution by design. Half a page per object is the target. It was never brittle if it never broke. Default standards-body instincts (defensive enumeration, MUST/SHOULD/MAY granularity, edge-case prose) are explicitly resisted. The framework underneath (the character_engine + character_receipts_engine set) is dense; the protocols on top are thin; total weight is correctly distributed.

Protocols and framework documents for MPA (Metastable Propositional Algebra). The canonical theory, the RFC sequence that turns it into a checkable contract, and the architectural commitments that govern how those documents fit together.

mpa-atlas is upstream of every other repo in the constellation. Substrates speak to it (drivers translate substrate-native data into the canonical representation it defines); realizers consume from it (the realizer-interface RFC defines what they receive); the authoring environment (mpa-character) emits artifacts shaped to its spec-object protocol.

What's here

• framework/character_engine.md — the operational source of truth (claims axis). Continuously maintained alongside the RFC sequence; every protocol revision reads from this file. One phenomenology, two readings — a STRUCTURAL projection (the discrete operator algebra $\Sigma = {C, S, K, R}$, Boolean as the $D \to \infty$ limit, the Compression Axiom, the trail-class metric, per-regime universality invariants) and a CHARACTER projection (continuous physical economics of sustained NESS traversal: chit unit, universal two-mode kernel, heat-tax tower, gFDR signatures, the character deformation chart, five leading-order posits) — joined at one shared spine (the Boolean→MPA deformation). Dense; self-contained; claim-only; substrate-neutral.
• framework/character_receipts_engine.md — line-keyed justifications behind the engine claims, the CORRECTIONS & PROMOTED REFINEMENTS log, and the prior-art map. Append-only during prove-as-you-go work; the file that makes unabridged reconstruction tractable.
• framework/character_frontier.md — the maturity ledger / GATES state machine (steeping → sharpening → battery → staked → promoted → core) that quarantines provisional work.
• framework/character_prior_art.md — the borrowed-results axis: pa: keys, what each import borrows, and the reading MPA adds. Plus character_applications.md, character_fdr_treatment.md, character_units.md, and the methodology reference translating_FDR_steps.md.
• framework/archive/ — superseded canonical docs and the frozen published mpav1_* snapshot (mpav1_compressed.md / mpav1_receipts.md / mpav1_unabridged.md, the citable paper). Provenance only; not authoritative for operational lookups. If a live mpa_* file and the archived snapshot disagree, the live file wins.
• architecture/MPA_Architectural_Block-In.md — the architectural commitments made when the program shifted from "build the translator" to "specify the input contract first." Five foundational principles: color-management discipline, observer-driven scale management, demand-bounded sufficiency, singular working-space path, thin-RFC discipline. Block-in resolution: right shapes in the right places, surfaces not yet refined. The RFCs refine specific pieces against this block-in.
• rfcs/MPA-RFC-1_Spec-Object.md — RFC-1, the spec-object protocol. The typed configuration $(V, E, \Gamma, D, \tau_{obs}, P, \langle\text{demand-envelope}\rangle)$ and what it means to be a valid instance. v0.2 (thin-pass; foundational principles inherited from the block-in).
• rfcs/MPA-RFC-2_FDR-Signatures.md — RFC-2, FDR-signature contract. The exchange artifact $(\text{object_ref}, \text{regime_class}, \text{parametric_plot}, \text{universality_tuple}, \tau_{obs}, \text{measurement_envelope})$, anchored on the framework's per-regime universality invariants ${X_c, \alpha_s, P_s, X_r, N_f}$. v0.1 thin-pass, no block-in stage.
• rfcs/MPA-RFC-V_Reference-Vocabulary.md — RFC-V, reference vocabulary. Canonical-label registry for cross-cutting concepts (operators, regimes, universality invariants, intents, compression-axiom symbols) + disambiguation rules ($C$ vs. $\mathcal{C}$; $\epsilon$ vs. $\varepsilon_n$). v0.1 thin-pass.
• rfcs/MPA-RFC-RI_Realizer-Interface.md — RFC-RI, realizer interface. The output-device-transform analog: $R_\text{doc} = (\text{spec_ref}, \text{intent}, \text{canonical_snapshot}, \text{signature_targets}, \text{acceptance}, \text{realizer_class_target})$. v0.1 thin-pass; downstream of RFC-1 / RFC-S / RFC-2 / RFC-V.
• rfcs/MPA-RFC-3_Consistency-Completeness.md — RFC-3, consistency & completeness. Cross-artifact predicates that no single RFC owns: C1–C5 (spec ⊆ driver gamut, intent / realizer-class compatibility, persistence-depth bound) + K1 (signature_targets cover spec elements). v0.1 thin-pass.
• rfcs/MPA-RFC-S_Scale-Management.md — RFC-S, scale management. v0.2 thin-pass: RG flow as foundational structure; canonical representation as the fixed-point set of the flow; substrate gamut as the RG trajectory image; five-intent enumeration; compactification-points table replaces per-intent edge-case enumeration.
• rfcs/MPA-RFC-S_Scale-Management_Block-In.md — RFC-S v0.1 block-in, preserved as honest-scope reference. Documents the standards-body weight that thin-RFC declines to import; not authoritative for operational lookups.
• reference-drivers/surface-code-qec.md — first reference driver. Surface-code QEC translated into MPA's canonical representation, hand-built from the framework engine. Subsequent drivers (substrate-implementation drivers in mpc-* repos) are validated against this one via the round-trip protocol of RFC-S §5.

RFC sequence

RFC	Topic	Status
RFC-1	Spec object	v0.2 (thin-pass; foundational principles inherited)
RFC-2	FDR-signature contract	v0.1 (thin-pass, no block-in stage)
RFC-3	Consistency & completeness	v0.1 (thin-pass)
RFC-S	Scale management	v0.2 (thin-pass; v0.1 block-in preserved as honest-scope reference)
RFC-V	Reference vocabulary	v0.1 (thin-pass)
RFC-RI	Realizer interface	v0.1 (thin-pass)

The RFC sequence is the substrate-neutral working space's specification. Substrate variation lives in drivers; user-intent variation lives at the realizer-interface intent flags; everything else is one shape per RFC version (no profile branching at the working-space layer).

Foundational principles (v0.2 lands these)

Three disciplines borrowed from upstream domains, promoted to load-bearing architectural commitments:

1. Color-management discipline. Substrate-native / canonical / realizer-output as three layers with declared, named, versioned, swappable transforms between them. Working space is substrate-neutral by construction.
2. Observer-driven scale management. $\tau_{obs}$ is the camera. The canonical representation is observer-relative; cross-scale composition is camera motion, not transform invocation; no scale-class taxonomy baked in.
3. Demand-bounded sufficiency. The CD-and-human-ears precedent — the framework commits to enough representation for the demands placed on it, not maximally faithful to the substrate. The MPA is not the bottleneck. Drivers declare a demand envelope; the canonical representation is sized to it.

The block-in document carries the long-form treatment; RFC-1 v0.2 will canonicalize.

Sibling repos

Repo	Role
mpa-character	Authoring environment. Emits spec objects against this repo's RFC-1. Formerly "Substrate Synthesizer."
mpa-central	Cross-substrate coordination, library, pre-registrations, RULES.md. Not a parent — a known place.
mpa-brain	v8 substrate (cognitive architecture).
mpa-visualizer	Cross-substrate renderer.
mpc-quantum / mpc-glass / mpc-sat / etc.	Substrate implementations. Drivers translate substrate-native into canonical representation.

Discipline

• One shape per RFC version. Plurality lives in drivers (substrate-conditional), realizer-interface intent flags (user-intent-conditional), and version succession (time-conditional). Not at the working-space layer.
• Drift-resistant. Architectural commitments that get baked in early are the ones that don't get baked in wrong. Foundational principles land in v0.2's body, not just in commentary.
• Versioned, not branched. RFC-1 v0.1 → v0.2 → v1.0. No RFC-1A / RFC-1B.