[jamesyc]

Summary

Seven unchanged accepted sources derive an actual three-tape positioned paired-track read, fresh marked output, and return to global home. The controller charges both handoffs and preserves the full occupied source store, supplied unary control and carried scratch. The original entrance volume V yields time ≤ 7V and every-prefix represented tape cells ≤ 2V.

Author-checked context

κ = 836330098538459/500000000000000000 = 0.001672660197076918, unchanged selected PR1094 context only.

Scope

Finite full-theorem coverage: actual prepared runs, exact first halt and all-prefix storage including terminal stuttering. Conditional interfaces: supplied marked store/unary position, separate empty output, fixed track selector and successful structural locate when keyed. Key search, position production, physical encoding/initialization, arbitrary old extraction-register restoration, selected recursive runtime and full multiplication remain outside this endpoint.

Evidence and reuse

43 complete standard-only probes and 12 printed types are bound to exact source hashes. Two PackedMetadataSlots style lints remain; six other roots are diagnostic-free. Historical preparation labels are preserved with later acceptance made explicit. Seven sources / 85,710 bytes reuse 27 immutable public/import-derived prerequisites, with complete 34-module closure. PR2235 generic framing/caller/serializer work is acknowledged; no generic novelty or priority claim. No accepted source was changed or replayed for publication.

Later provider comparison

PR2411 supplies general mapped source-preserving copy, binary-counted seek and marked return. This package preserves the already accepted three-tape paired-store/unary-block ABI and its exact 7V/2V endpoint; it is not presented as new generic infrastructure. Exact provider links and representation differences are documented in the README.

Exact adoption

Publication parent: 0fdd7d8. The five selected-result, assembly, selected-source and emitter blobs match the previously checked context exactly; contextual kappa is unchanged. No accepted proof was rerun for this adoption.