Proof Semantics

1. Purpose of This Document

This document defines the semantic scope and limits of Horizon evidence.

It exists to:

• clarify what a sealed fact establishes as evidence,
• explicitly delimit what Horizon does not assert,
• prevent misinterpretation or requalification of Horizon evidence.

Horizon evidence is factual, declarative, and non-interpretive.

This document is a semantic responsibility boundary between:

• Horizon (integrity of evidence),
• and Horizon clients (truth, legitimacy, interpretation).

2. Core Semantic Principle

A Horizon proof establishes the existence of a declaration - nothing more.

It proves that:

• a declaration was received,
• it was sealed at a precise time,
• it was attributed as declared,
• it belongs to a stream of related facts.

It does not prove intent, legitimacy, correctness, causality, or outcome.

3. What a Sealed Fact Proves

A sealed fact proves, and only proves, that:

This proof is:

• append-only,
• tamper-evident,
• independently verifiable.

4. What a Sealed Fact Does NOT Prove

A sealed fact does not prove:

• that the declaration is true,
• that the declaration reflects intent,
• that the declaration was authorized,
• that an action occurred at the declared time,
• that an action occurred at all,
• that one fact caused another,
• that responsibility or fault exists,
• that any policy, rule, or obligation was satisfied.

Horizon does not infer, compute, or assess meaning.

5. Time Semantics

Horizon assigns a single authoritative time: sealed_at.

sealed_at represents:

• the moment Horizon sealed the declaration,
• the moment from which the fact becomes provable.

Horizon does not assert:

• when an action actually occurred,
• when an observation was made,
• whether client clocks were synchronized.

Any client-provided timestamps:

• belong to the payload,
• are not authoritative,
• are not validated or reconciled by Horizon.

6. Actor Attribution Semantics

Horizon does not prove:

• the biological identity of a human,
• the legitimacy of the actor,
• the authority or role associated with the declaration.

The actor field represents declared attribution.

Horizon:

• records attribution as provided through a technical channel (API, email, system integration),
• proves the provenance of the declaration via that channel.

Responsibility for the truth, legitimacy, and authority of a declaration remains with the declaring party.

7. Stream Semantics

A stream is a container of related facts.

Horizon:

• does not define workflow steps,
• does not enforce order beyond sealing time,
• does not define completion or closure,
• does not infer process state.

Streams are never closed by Horizon. New facts may be appended at any time. Any notion of "process", "decision", or "outcome" is external to Horizon.

8. Fact Correlation and Causality

Relationships between facts within a stream (such as parent references or shared identifiers) are provided by client systems.

Horizon:

• does not infer causality,
• does not compute dependency,
• does not assert procedural sequence.

Any perceived sequence, dependency, or workflow is an interpretation external to Horizon and must not be attributed to Horizon itself.

9. Incomplete Streams and Silence

Horizon does not interpret the absence of facts.

If no additional fact is appended after a declaration:

• Horizon does not infer failure,
• does not infer success,
• does not infer abandonment,
• does not infer intent or negligence.

Silence, delay, or incompleteness are not evidence within Horizon. Interpretation of incomplete streams depends entirely on external context.

10. Interpretation Boundary

All interpretation happens outside Horizon.

Horizon evidence may be used by humans, organizations, auditors, courts, or regulators.

Horizon itself:

• does not interpret,
• does not recommend,
• does not conclude.

11. Legal and Regulatory Positioning

Horizon evidence is technical, factual, and neutral.

It does not constitute:

• a decision,
• an authorization,
• a sanction,
• a policy evaluation,
• a compliance assertion.

Horizon is a witness, not a judge.

12. Canonical Summary

Horizon produces evidence of declaration, not evidence of correctness or legitimacy. This principle governs all Horizon proofs.

13. What This Document Explicitly Prevents

• Misuse of Horizon as an approval system
• Requalification as governance or compliance tooling
• Attribution of responsibility to Horizon
• Over-interpretation during audits or investigations