Definition and machine model

FPRD-D36

Bounded simultaneous record transducer

Exact statement

A bounded simultaneous record transducer chooses, from a fixed-radius observation of old records, one bounded labelled graph of fresh records whose fields may target old addresses or any active fresh slot, including self, forward, and mutually cyclic references; no fresh record is inspected while the plan is chosen.

StatusSelf-contained repaired definition
External reviewNo documented external or specialist review of this FPRD result is recorded.

Context

An occurrence record and the final cell of its new receipt rope point to one another. A sequential allocate-then-link model cannot express that same-step cycle, although a scaffold node can encode it with SELF.

Definitions

  • The constants are the number s of roots, fresh-slot bound A, pointer-field bound q, and old dereference radius r.
  • A logical pointer is missing or a pair (time, slot); a transition chooses a complete finite adjacency table from old observations.

Proof or evidence

The definition is stated in the paper, theorem inventory, and proof audit, with explicit self-loop, forward-reference, and mutual-cycle examples.

Verification notes

The imported topologically ordered allocator was rejected because it excluded the construction's owner-to-rope-to-owner cycle. Draft 2 uses simultaneous allocation explicitly and forbids same-step inspection of fresh payloads.

Limitations

  • Simultaneous allocation is a finite graph specification, not a domain-theoretic fixed point.
  • The definition alone does not show that a particular persistent program has bounded observation or allocation.

Open work

Compare the model with established cyclic term-graph and simultaneous-allocation formalisms without assuming equivalence.

Notes

This corrects the imported PC-83 source model, which allowed only already-constructed fresh targets even though its receipt equation created a same-step semantic cycle. Simultaneous allocation is a finite graph specification, not a domain-theoretic fixed point or permission to inspect a newly allocated record during the same transition.