Public evidence

math.geometry.circle

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

Open calculator API Capability Download JSON MCP Review policy

Verification

10/10 calculation tests · Production surface contract 3/3

Golden tests 3 / 3
Boundary tests 2 / 2
Property tests 5 / 5
Production surface contract 3 / 3
Engine tested Yes
Source checked Yes
Artifact integrity PASS
Production attestation Embedded snapshot: unpublished · Build schema 1.0.0 ready · Semantic contract ✓ · Attestation report not published on origin · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-16T06:44:24.909Z
Semantic contract PASS
Evidence attested at 2026-09-16T06:44:24.203Z
Last production check 2026-09-16T06:44:24.203Z
Public / cache —
Origin —
Supplemental domain review Not performed
Named expert review Not performed

release artifacts aligned PASS
schema valid input executes PASS
engine success output validates schema PASS

Fingerprint sha256:fb804e3cafe6a556d70771cabc3bc8821b7682e90dab13b739c3f2f905a1b073

Input schema sha256:9995e7f33c9a37c97d1ee902e646b72df19e0cb77c66356947c16b1bba7132db · Output schema sha256:ad9ce23737cb23424ed78ff02f643b264a9066cd42adac9bcf113c56da4d3ec8 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: circle
Engine: circle
Engine build: 2026-09-16
Evidence core: 2026-09-16T15:14:48.779Z
Rendered: 2026-09-16T22:38:08.875Z
Last reviewed: —

Assumptions

Euclidean plane
Not spherical geometry
Not Pythagorean-only

Limitations

Not a²+b²=c² — use /calc/math/pythagorean
r ≤ 0 → VALUE_MUST_BE_POSITIVE
Spherical geometry is out of scope

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

ISO 80000-2:2019 Quantities and units — Mathematics

Published checks

Golden, boundary, and property cases included in this evidence build.

ID	Kind	Status	Detail
`golden-unit-circle`	golden	pass	Expected diameter=2 · Actual mode=from_radius · r=1 · diameter=2 · circumference=6.28318530718 · area=3.14159265359 · formula=C = 2πr, A = πr²
`golden-circle-area`	golden	pass	Expected area=3.141592653589793 · Actual mode=from_radius · r=1 · diameter=2 · circumference=6.28318530718 · area=3.14159265359 · formula=C = 2πr, A = πr²
`golden-arc-semicircle`	golden	pass	Expected arc_length=6.283185307179586 · Actual mode=arc · r=2 · diameter=4 · circumference=12.5663706144 · area=12.5663706144 · theta_deg=180 · theta_rad=3.14159265359 · arc_length=6.28318530718
`boundary-circle-zero`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-circle-pythag`	boundary	pass	Expected INVALID_MODE · Actual INVALID_MODE
`property-circle-d`	property	pass	d=2r
`property-circle-c`	property	pass	C=2πr
`property-circle-a`	property	pass	A=πr²
`property-circle-roundtrip`	property	pass	area→r
`property-circle-arc`	property	pass	semicircle