RESEARCH • POST‑INCIDENT • CITABLE

Dynamic CALL in COBOL: Why Runtime Target Resolution Breaks Provability

Authority posture: This research is cited inside authority records. It is not advice. It explains why authority terminates.

Post‑incident framing: this page defines a provability boundary that can terminate authority in regulated decisions. It is written to be cited inside authority records and to survive scrutiny.

Scope

This page explains what the boundary is, why deterministic guarantees collapse, and how authority records must describe termination without predicting outcomes for other systems.

What “dynamic CALL” means in COBOL

A literal CALL references a fixed program name. The call target can be resolved from artifacts if the called program is included and naming is consistent.

A dynamic CALL uses an identifier, a variable whose value at runtime determines the program invoked. The value may be loaded from files, tables, databases, message payloads, or constructed from substrings.

In many estates, dynamic CALL is a routing mechanism. It may be bounded in practice. But provability is about what is guaranteed by artifacts, not what is likely in operations.

In practice, estates often combine multiple boundary classes. This page isolates one class so that authority language remains precise and citable.

Legacy Lens publishes precedent and invites comparison. It does not predict what will occur in other systems. The boundary definition is provided as a standard reference.

If an authority record cites this page, it should do so to define the evidentiary limit encountered in the analyzed corpus under the declared context.

Why call graph provability collapses

Static proof requires a deterministically bounded set of possible call targets derived from artifacts. Dynamic CALL can make that set unbounded unless the program name construction is itself provably bounded.

Even when bounded, dynamic dispatch often introduces an evidentiary gap: the mapping between identifiers and targets may live outside the analyzed scope (tables, configuration, region state).

Authority cannot extend beyond an unproven dispatch mapping. If a transformation changes routing, the institution must be able to prove equivalence. Dynamic CALL prevents a blanket proof claim.

In practice, estates often combine multiple boundary classes. This page isolates one class so that authority language remains precise and citable.

Legacy Lens publishes precedent and invites comparison. It does not predict what will occur in other systems. The boundary definition is provided as a standard reference.

If an authority record cites this page, it should do so to define the evidentiary limit encountered in the analyzed corpus under the declared context.

Why “it works in production” is not a proof

Operational success demonstrates that observed paths function. It does not prove that unobserved dispatch targets are impossible.

Post-incident review asks whether an unexpected path could have occurred. Dynamic CALL keeps that possibility open unless the mapping is provable from artifacts.

Legacy Lens treats dynamic CALL as an absolute provability boundary when the target set cannot be proven from the submitted artifacts alone.

In practice, estates often combine multiple boundary classes. This page isolates one class so that authority language remains precise and citable.

Legacy Lens publishes precedent and invites comparison. It does not predict what will occur in other systems. The boundary definition is provided as a standard reference.

If an authority record cites this page, it should do so to define the evidentiary limit encountered in the analyzed corpus under the declared context.

Authority record language

Authority records should say: runtime target resolution is unprovable from artifacts; authority terminates at this boundary.

They should list the call sites with file/line evidence. They should avoid advice and prediction.

They should cite this page when dynamic CALL is a termination driver.

In practice, estates often combine multiple boundary classes. This page isolates one class so that authority language remains precise and citable.

Legacy Lens publishes precedent and invites comparison. It does not predict what will occur in other systems. The boundary definition is provided as a standard reference.

If an authority record cites this page, it should do so to define the evidentiary limit encountered in the analyzed corpus under the declared context.

How to cite this research in an authority record

Use language such as:

This decision references Legacy Lens research (RESEARCH_DYNAMIC_CALL_RISK). The analysis explains a provability boundary where deterministic guarantees collapse. Where provability terminates, authority terminates under the declared governance context.

Explicit non‑claims