ball_float Conformance

Claim

The current strict ITF1788 gate executes 4,656/4,656 selected cases with no failed, unsupported, or diagnostic rows. This is a claim about the pinned corpus revision, selected operation phases, and runner precision—not a claim of complete IEEE 1788 implementation.

Semantic Oracle

Expected results are compared by set meaning: endpoint containment, set relations, boolean relations, overlap states, numeric observations, and decorations use operation-specific comparators. A conservative interval may be valid when the contract permits widening; an enclosure that excludes an exact result is never valid.

Supported Phases

The strict matrix covers sets, relations, observations, cancellation, add/subtract/multiply/divide, elementary core, exponential/logarithmic functions, general power, trigonometric functions including atan2, FMA, integer power, and extrema. Phase operation sets are disjoint so a row is never counted twice.

Decorations And Fallbacks

Empty, Entire, and decorated NaI are separate states. Elementary kernels use directed dyadic certificates. When range reduction cannot be certified, sin/cos return [-1,1] and tan returns Entire; that preserves inclusion but does not promise tightness.

Exclusions

Reverse interval operations, every decoration rule outside the selected phases, arbitrary endpoint formats, and unpinned upstream revisions remain outside the claim.

Reproduction

just conformance smoke interval
just conformance fetch interval itf1788
just gate interval 8

See the interval data guide for provenance, phase counts, strict-mode behavior, and failure triage.