New on SSRN: Ariadne's Thread, a measurement-theoretic method for legal openness. Read the paper

Determinacy and Gray Areas

Verified substrate

The fixed body of checked legal materials that every reasoner in a measurement receives: which authorities are binding, persuasive, limited or overruled, which propositions each supports, who bears which burden, and which procedural standard controls.

First used in From the Supreme Court Machine to Ariadne's Thread

The substrate is a contract, not a database label; a list of semantically similar cases is not a verified legal surface. It must be identical across postures, and no language model may write a citation or a validity verdict into it.

Without that discipline, cross-posture dispersion mixes posture with differential legal error, and the instrument measures the engineer's retrieval choices rather than the law. If one reasoner cites a live case, another invents one and a third forgets a controlling rule, the resulting spread is input failure, not openness.

Whether a substrate meets the contract at scale is stated as a conjecture (C-Ground), not assumed. If the substrate is wrong, the instrument faithfully measures the openness of the wrong law.

Related terms

Z (posture dispersion)Posture-conditioned reasoner Structural reliability Authority health

Related frameworks

Frameworkstable

Posture Dispersion (Z)

Hold verified law fixed, vary only the judicial posture across a declared panel, subtract the instrument's own replicate noise, and the normalized dispersion that remains, Z, measures how open a procedural question is.

Determinacyv1.0

Used in

18 Jul 2026Ariadne's ThreadLegal Determinacy as Measured Dispersion across Posture-Instantiated AdjudicatorsRoss Brodskiy and Nathan Pokov · 8 min readPaperDeterminacy 18 Jul 2026Before You FileWhat a Measured Openness Score Would Change About Budget, Settlement and Motion Strategy, and What to Ask Before You Trust OneTom Brennan · 7 min readField GuideDeterminacy 18 Jul 2026From Hercules to AriadneHow a Half-Century Quarrel in Jurisprudence Became a Quantity, and What the Quantity Cannot SettleJulian Fenwick · 10 min readEssayMachine Jurisprudence 18 Jul 2026Posture, Standard, and the Shape of DiscretionA review of Brodskiy and Pokov, Ariadne's ThreadEleanor Voss · 6 min readReviewDeterminacy 18 Jul 2026The Thread in the CourtroomSome Cases Have One Path and Some Have Many. What Would It Mean to Measure the Difference?Elena Voss · 9 min readEssayDeterminacy 18 Jul 2026Who Holds the Thread?A review of Brodskiy and Pokov, Ariadne's ThreadNora Kestrel · 6 min readReviewDeterminacy 18 Jul 2026Z, FormallyInputs, Rules, Inference Procedure, Outputs: What Ariadne's Metric Measures and What Its Theorems ProveAda Mercer · 9 min readEssayDeterminacy 21 Jun 2026From the Supreme Court Machine to Ariadne's ThreadRoss Brodskiy · 3 min readEssayDeterminacy 20 Jun 2026What Remains for the Judge When the Machine Has Already Verified the Law?Ross Brodskiy · 3 min readEssayMachine Jurisprudence 21 Apr 2026The Four Laws of System Design for Computational LawFour ordered design rules for legal AIRoss Brodskiy · 2 min readEssaySystem Design 15 Apr 2026The Promise FulfilledHow Proposition-Level Legal Knowledge Representation at Corpus Scale Realizes Three Decades of Computational JurisprudenceRoss Brodskiy · 5 min readPaperKnowledge Engineering