Evidence and Result Contract

Bifrost results report both the evidence found and how much of the requested search completed. A row can be useful positive evidence without proving that the search was exhaustive. A completed search can return no rows and support a bounded absence claim.

Proof and completeness

Every semantic edge or relation carries two independent fields:

Field	Complete value	Limited value
Proof	proven when retained evidence establishes the relation	unproven with a reason when the row is a structured candidate
Completeness	complete when evidence covers the requested semantics at that site	partial with a reason when a frontier remains

Neither dimension implies the other. A proven edge can be one known edge in an incomplete dispatch set. A complete candidate enumeration can contain an unproven alternative when the available semantics cannot select one runtime target.

When paths differ in proof or completeness, the solver keeps the incomparable alternatives. It discards a path only when another path dominates its evidence.

Request outcomes

At the provider boundary, outcomes remain typed:

Outcome	Meaning	May contain useful data?	Supports a clean zero?
complete	The requested supported work completed under its stated scope	Yes	Yes, inside that exact scope
ambiguous	More than one structured candidate remains	Yes	No
unknown	The provider cannot establish the requested relation	Sometimes	No
unsupported	The selected capability is unavailable for this input	Sometimes	No
unproven	A structured result exists without sufficient proof	Yes	No
exceeded_budget	A named work limit stopped the request	Sometimes	No
cancelled	Cooperative cancellation stopped the request	Sometimes	No

Policy and extension surfaces may use wire labels such as frontier_bounded, budget_bounded, inconclusive, or refused. Those labels preserve the same semantic distinctions. A transport error remains distinct from an analysis outcome.

Scope is part of the claim

Completeness is scoped to the request that produced the result. Relevant scope includes:

• workspace root and generation;
• selected languages, files, and path filters;
• operation and relation kinds;
• call depth and semantic frontier;
• active semantic-model set and dependency fingerprint;
• result, graph, source-byte, and traversal limits; and
• witness and provenance retention limits.

For example, a complete three-file search supports a three-file absence claim. A procedure-local CFG query supports only that procedure-local claim.

Positive evidence and authoritative absence

A partial result supports only a narrow positive claim: Bifrost returned this source-backed edge.

An empty result supports authoritative absence only when all relevant conditions hold:

1. the request and transport succeeded;
2. the intended workspace generation was analyzed;
3. the capability was supported for every selected input;
4. execution completed without cancellation or a budget boundary;
5. result and provenance retention did not truncate the claim; and
6. the absence statement repeats the actual analysis scope.

Provenance and source mapping

Stable identities support comparison, caching, and remapping of a semantic subject. Source mappings let a person or client inspect why the subject or relation was returned. Declaration identity remains independent of source ranges.

Derived results can have several provenance paths. A bounded response may retain only some of them, with omission status distinguishing one witness from an exhaustive witness set.

A retained report identifies its artifacts, declarations, events, policies, and sources before mapping them into the current presentation.

Canonicalization across clients

Canonicalization happens before protocol-specific rendering. Equivalent LSP, MCP, CLI, and library operations are expected to preserve result ordering, identity, completion, diagnostics, and evidence. Adapters can map transport errors or envelope fields. Canonical analysis execution and result interpretation remain fixed.

Differential tests can compare that canonical payload across adapters independently of transport timing and queue metadata.

Cache consequence

Only complete, current artifacts are eligible for complete-value caches. Cancelled, stale, budget-exhausted, store-failed, or semantically partial work remains scoped to the request that produced it.

The storage chapter specifies the corresponding complete-value cache mechanics.

Operational wording is in Agent Result Safety. The identities and artifacts needed to replay a result are in Reproduce an Analysis.