Public evidence

mechanical.statics.ladder_rough_wall

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

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Verification

7/7 calculation tests · Production surface contract 6/6

Golden tests 3 / 3
Boundary tests 4 / 4
Property tests 0 / 0
Production surface contract 6 / 6
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Production attestation Embedded snapshot: unpublished · Build schema 1.0.0 ready · Semantic contract ✓ · Attestation report not published on origin · Live production status STALE (6 capabilities; 189 remain CURRENT) @ 2026-09-23T14:00:05.385Z
Semantic contract PASS
Evidence attested at 2026-09-23T02:27:54.588Z
Last production check 2026-09-23T02:27:54.588Z
Public / cache —
Origin —
Supplemental domain review Not performed
Named expert review Not performed

release artifacts aligned PASS
schema output required declared PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS
rest success payload validates schema PASS

Fingerprint sha256:1c2f407bd2ba8b9d8e33d405ecde123c5cbdfedd59f70125423711dd1590434e

Input schema sha256:04ea699edcd3d266d975d539c8f89af314f901a6bfb732b7e83f35b8ccdb9e1c · Output schema sha256:73d88426cccf42a70e707412bb3e2f1ce46bdbaa93923828dfb801c169191e5e · 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: ladder-rough-wall
Engine: ladder-rough-wall
Engine build: 2026-09-23
Evidence core: 2026-09-23T12:25:21.407Z
Rendered: 2026-09-23T14:21:08.537Z
Last reviewed: —

Limitations

The ladder is uniform and the weight acts at mid-length
Both surfaces are at impending slip
μwall = 0 is the smooth-wall case
Not a person on the ladder, a wedge, a screw, or a belt

Sources

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

Hibbeler, Engineering Mechanics: Statics — Dry friction — ladder with friction at both surfaces
Supports: At impending slip on both surfaces, tanθ = (1 − μ_floor μ_wall) / (2 μ_floor) for a uniform ladder

Published checks

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

ID	Kind	Status	Detail
`golden-smooth`	golden	pass	Expected mode=angle · theta_deg=45 · N=100 · F=50 · B=50 · F_wall=0 · model=ladder_rough_wall · Actual model=ladder_rough_wall · W=100 · mu_floor=0.5 · mu_wall=0 · mode=angle · theta_deg=45 · N=100 · F=50
`golden-both`	golden	pass	Expected mode=angle · theta_deg=47.72631099390627 · N=89.28571428571428 · F=35.714285714285715 · B=35.714285714285715 · F_wall=10.714285714285714 · Actual model=ladder_rough_wall · W=100 · mu_floor=0.4 · mu_wall=0.3 · mode=angle · theta_deg=47.72631099390626 · N=89.2857142857 · F=35.71428571428
`golden-any`	golden	pass	Expected mode=any · Actual model=ladder_rough_wall · W=100 · mu_floor=1 · mu_wall=1 · mode=any · solver=friction + math.linear_algebra solve order 2 · convention=Uniform ladder, weight at mid-length. Both surfaces are at impending slip. μfloor·μwall ≥ 1, so the ladder holds at every angle in (0, 90). Reactions are not unique.
`boundary-weight`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-floor`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-wall`	boundary	pass	Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE
`boundary-missing`	boundary	pass	Expected MISSING_REQUIRED_INPUT · Actual MISSING_REQUIRED_INPUT