| Observable | https://uor.foundation/observable/Observable | http://www.w3.org/2002/07/owl#Thing | | A measurable quantity in the UOR Framework. All observables are kernel-computed and user-consumed. |
| StratumObservable | https://uor.foundation/observable/StratumObservable | https://uor.foundation/observable/Observable | | An observable measuring stratum-level properties: position within the ring's layer structure. |
| MetricObservable | https://uor.foundation/observable/MetricObservable | https://uor.foundation/observable/Observable | | An observable measuring geometric distance between ring elements under a specific metric. |
| PathObservable | https://uor.foundation/observable/PathObservable | https://uor.foundation/observable/Observable | | An observable measuring properties of paths through the ring: path length, total variation, winding number. |
| ReductionObservable | https://uor.foundation/observable/ReductionObservable | https://uor.foundation/observable/Observable | | An observable measuring reduction properties: the length and count of operation sequences. |
| CatastropheObservable | https://uor.foundation/observable/CatastropheObservable | https://uor.foundation/observable/Observable | | An observable measuring catastrophe-theoretic properties: thresholds at which qualitative changes occur in the partition. |
| CurvatureObservable | https://uor.foundation/observable/CurvatureObservable | https://uor.foundation/observable/Observable | | An observable measuring the curvature of the UOR geometry: the gap between ring-isometry and Hamming-isometry for a given transform. |
| HolonomyObservable | https://uor.foundation/observable/HolonomyObservable | https://uor.foundation/observable/Observable | | An observable measuring holonomy: the accumulated transformation when traversing a closed path in the ring. |
| SpectralObservable | https://uor.foundation/observable/SpectralObservable | https://uor.foundation/observable/Observable | | ADR-049: an observable whose value is a structural reading of a digest's frequency-domain spectrum. Distinct from the seven internally-derived Observable categories (Stratum / Metric / Path / Reduction / Catastrophe / Curvature / Holonomy) — its values are Walsh–Hadamard parities at specific frequencies, not derivable from the framework's internal algebraic/topological structure. Foundation's typed observable `WalshHadamardParity` per ADR-049 falls under this subclass; predicates over its values enter the typed-commitment surface per ADR-048 as `SingletonCommitment<WalshHadamardParity>` operands. |
| ValueThresholdObservable | https://uor.foundation/observable/ValueThresholdObservable | https://uor.foundation/observable/Observable | | ADR-040 + ADR-049: an observable whose value is a byte-sequence threshold comparison reading of a digest. Distinct from the seven internally-derived Observable categories (Stratum / Metric / Path / Reduction / Catastrophe / Curvature / Holonomy) and from SpectralObservable / AxisProjectionObservable — its values carry from `(digest as big-endian unsigned integer) <= (target as big-endian unsigned integer)`, the predicate form ADR-040 named when it committed `type:LexicographicLessEqBound`. Foundation's typed observable `LexicographicLessEqThreshold` per ADR-049 falls under this subclass; the canonical search-cost commitment alias `TargetCommitment = SingletonCommitment<LexicographicLessEqThreshold>` per ADR-048 consumes it. The ConstraintRef::Bound.args_repr canonical-string-form encoding for ValueThresholdObservable arguments carries the target byte sequence as the bound's argument directly. |
| AxisProjectionObservable | https://uor.foundation/observable/AxisProjectionObservable | https://uor.foundation/observable/Observable | | ADR-038: an observable whose value is the axis-realized projection of typed sites through an application-declared AxisTuple kernel per ADR-030. Distinct from the seven internally-derived Observable categories (Stratum, Metric, Path, Reduction, Catastrophe, Curvature, Holonomy) — its values carry from the substrate-extension surface (axis kernels), not from the framework's internal algebraic / topological structure. The closed-catalog discipline holds: foundation owns the subclass; applications consume catalog variants through canonical-string-form `args_repr` on `ConstraintRef::Bound`. The args_repr encoding (per ADR-038) is `axis_address=<hex>;kernel=<symbolic>;sites=<site-list>[;target=<target-spec>]` — axis identification by content-address (AXIS_ADDRESS per ADR-030), not by tuple position, so the encoding is application-invariant. |
| RingMetric | https://uor.foundation/observable/RingMetric | https://uor.foundation/observable/MetricObservable | | Distance between two ring elements under the ring metric: d_R(x, y) = |x - y| mod 2^n. |
| HammingMetric | https://uor.foundation/observable/HammingMetric | https://uor.foundation/observable/MetricObservable | | Distance between two ring elements under the Hamming metric: the number of bit positions where they differ. |
| IncompatibilityMetric | https://uor.foundation/observable/IncompatibilityMetric | https://uor.foundation/observable/MetricObservable | | The metric incompatibility between two ring elements: the divergence between their ring-metric and Hamming-metric distances, measuring geometric curvature. |
| ValueModObservable | https://uor.foundation/observable/ValueModObservable | https://uor.foundation/observable/MetricObservable | | Observes a Datum's value modulo a configurable modulus. Used as the bound observable for BoundConstraint instances representing residue and affine constraint kinds (residueConstraintKind, affineConstraintKind). |
| GroundingSigma | https://uor.foundation/observable/GroundingSigma | https://uor.foundation/observable/Observable | | Observes the grounding completion ratio σ ∈ [0, 1] of a context, where σ = 1 indicates the ground state (state:GroundedContext). Backs the sigma_metric BaseMetric accessor on Grounded<T>. |
| JacobianObservable | https://uor.foundation/observable/JacobianObservable | https://uor.foundation/observable/Observable | | Observes the per-site Jacobian row of a Datum at a particular WittLevel, computed as the sequence of partial derivatives of the ring operation with respect to each site coordinate. Backs the jacobian_metric BaseMetric accessor on Grounded<T>; the Rust-side JacobianMetric<L> is parametric over the level marker. |
| StratumValue | https://uor.foundation/observable/StratumValue | https://uor.foundation/observable/StratumObservable | | The stratum index of a ring element. |
| StratumDelta | https://uor.foundation/observable/StratumDelta | https://uor.foundation/observable/StratumObservable | | The difference in stratum between two ring elements. |
| StratumTrajectory | https://uor.foundation/observable/StratumTrajectory | https://uor.foundation/observable/StratumObservable | | The sequence of strata traversed by a path through the ring. |
| PathLength | https://uor.foundation/observable/PathLength | https://uor.foundation/observable/PathObservable | | The length of a path through the ring, measured in operation steps. |
| TotalVariation | https://uor.foundation/observable/TotalVariation | https://uor.foundation/observable/PathObservable | | The total variation of a path: the sum of metric distances between consecutive elements. |
| WindingNumber | https://uor.foundation/observable/WindingNumber | https://uor.foundation/observable/PathObservable | | The winding number of a closed path: the number of times the path wraps around the ring. |
| ReductionLength | https://uor.foundation/observable/ReductionLength | https://uor.foundation/observable/ReductionObservable | | The number of operation applications in a reduction sequence. |
| ReductionCount | https://uor.foundation/observable/ReductionCount | https://uor.foundation/observable/ReductionObservable | | The number of distinct reduction sequences in a computation. |
| CatastropheThreshold | https://uor.foundation/observable/CatastropheThreshold | https://uor.foundation/observable/CatastropheObservable | | A critical value at which a qualitative change occurs in the partition structure. |
| CatastropheCount | https://uor.foundation/observable/CatastropheCount | https://uor.foundation/observable/CatastropheObservable | | The number of catastrophe events (qualitative partition changes) in a computation. |
| Commutator | https://uor.foundation/observable/Commutator | https://uor.foundation/observable/CurvatureObservable | | The commutator [f, g](x) = f(g(x)) - g(f(x)) of two operations, measuring their non-commutativity. |
| CurvatureFlux | https://uor.foundation/observable/CurvatureFlux | https://uor.foundation/observable/CurvatureObservable | | The integrated curvature over a region of type space: the total metric incompatibility accumulated. |
| Monodromy | https://uor.foundation/observable/Monodromy | https://uor.foundation/observable/HolonomyObservable | | The monodromy of a closed path: the net transformation accumulated when traversing a loop in the type space. |
| ParallelTransport | https://uor.foundation/observable/ParallelTransport | https://uor.foundation/observable/HolonomyObservable | | The parallel transport of a vector along a path: the canonical lift of the path to the tangent bundle of the ring. |
| DihedralElement | https://uor.foundation/observable/DihedralElement | https://uor.foundation/observable/HolonomyObservable | | An element of the dihedral group D_{2^n} acting on the type space. Each dihedral element induces an isometry of 𝒯_n. |
| MeasurementUnit | https://uor.foundation/observable/MeasurementUnit | http://www.w3.org/2002/07/owl#Thing | | A unit of measurement for observable quantities. Each MeasurementUnit individual names a specific unit (bits, ring steps, dimensionless) replacing the string-valued observable:unit property. |
| Jacobian | https://uor.foundation/observable/Jacobian | https://uor.foundation/observable/CurvatureObservable | | Site-by-site curvature decomposition. J_k measures the discrete derivative of the incompatibility metric at site position k: J_k = |d_R(x, succ(x)) - d_H(x, succ(x))| restricted to position k. |
| TopologicalObservable | https://uor.foundation/observable/TopologicalObservable | https://uor.foundation/observable/Observable | | An observable measuring a topological invariant of the resolution space. Topological observables are invariant under continuous deformations of the constraint configuration. |
| BettiNumber | https://uor.foundation/observable/BettiNumber | https://uor.foundation/observable/TopologicalObservable | | The rank of a homology group of the constraint nerve. β_k = rank(H_k(N(C))) counts the k-dimensional holes in the constraint configuration. |
| SpectralGap | https://uor.foundation/observable/SpectralGap | https://uor.foundation/observable/TopologicalObservable | | The smallest positive eigenvalue of the constraint nerve Laplacian. Controls the convergence rate of iterative resolution: larger gap = faster convergence. |
| ThermoObservable | https://uor.foundation/observable/ThermoObservable | https://uor.foundation/observable/Observable | | An observable measuring thermodynamic properties of the resolution process: residual entropy, Landauer cost, and reduction distribution statistics. |
| ResidualEntropy | https://uor.foundation/observable/ResidualEntropy | https://uor.foundation/observable/ThermoObservable | | S_residual: the residual Shannon entropy of the site distribution after partial resolution. Computed as S = (Σ κ_k − χ(N(C))) × ln 2 (IT_7b). Unit: Nats. |
| LandauerCost | https://uor.foundation/observable/LandauerCost | https://uor.foundation/observable/ThermoObservable | | The minimum thermodynamic cost (in units of k_B T ln 2) of erasing one bit of site uncertainty. The UOR ring operates at β* = ln 2 — the Landauer temperature. |
| LandauerBudget | https://uor.foundation/observable/LandauerBudget | https://uor.foundation/observable/ThermoObservable | | A sealed observable carrier for accumulated Landauer cost in nats. Monotonic within a single pipeline invocation. The UOR ring operates at the Landauer temperature (β* = ln 2), so this observable is a direct measure of irreversible bit-erasure performed by the computation up to the witness it accompanies. |
| ReductionEntropy | https://uor.foundation/observable/ReductionEntropy | https://uor.foundation/observable/ThermoObservable | | The Shannon entropy of the reduction distribution P(j) = 2^{−j}. At the Landauer temperature, this equals ln 2 per reduction step — each step erases exactly one bit of site uncertainty. |
| SynthesisSignature | https://uor.foundation/observable/SynthesisSignature | http://www.w3.org/2002/07/owl#Thing | | A named topological signature: a pair (realised Euler characteristic, realised Betti profile). Linked from TypeSynthesisResult. Allows comparison between the goal signature and the actually achieved signature. |
| SpectralSequencePage | https://uor.foundation/observable/SpectralSequencePage | http://www.w3.org/2002/07/owl#Thing | | A single page E_r of the quantum level spectral sequence. Carries the page index r and the differential d_r. The sequence converges when all differentials vanish — typically by E_3 for simple constraint configurations. |
| LiftObstructionClass | https://uor.foundation/observable/LiftObstructionClass | http://www.w3.org/2002/07/owl#Thing | | The cohomology class in H^2(N(C(T))) representing the LiftObstruction for a specific WittLift. The class is zero iff the obstruction is trivial. When non-zero, it indexes the specific site pair at Q_{n+1} that cannot be closed by the lifted constraint set alone. |
| MonodromyClass | https://uor.foundation/observable/MonodromyClass | http://www.w3.org/2002/07/owl#Thing | | A classification of a type's holonomy: the subgroup of D_{2^n} generated by all Monodromy observables computed over closed paths in the type's constraint nerve. Trivial iff every closed constraint path returns to its starting site assignment without net dihedral transformation. |
| HolonomyGroup | https://uor.foundation/observable/HolonomyGroup | http://www.w3.org/2002/07/owl#Thing | | The holonomy group of a ConstrainedType: the group of all Monodromy elements achievable by closed paths in the constraint nerve. Always a subgroup of D_{2^n}. Trivial iff the type has trivial monodromy everywhere; equals D_{2^n} iff paths involving both neg and bnot involutions are present. |
| ClosedConstraintPath | https://uor.foundation/observable/ClosedConstraintPath | http://www.w3.org/2002/07/owl#Thing | | A sequence of constraint applications forming a closed loop in the constraint nerve — beginning and ending at the same site assignment. The Monodromy of the loop is the net DihedralElement accumulated when traversing it. |
| PhaseBoundaryType | https://uor.foundation/observable/PhaseBoundaryType | http://www.w3.org/2002/07/owl#Thing | | A classification of phase boundary in the catastrophe diagram: period boundary (g divides 2^n − 1) or power-of-two boundary (g = 2^k). |
| AchievabilityStatus | https://uor.foundation/observable/AchievabilityStatus | http://www.w3.org/2002/07/owl#Thing | | The achievability classification of a topological signature in the morphospace. Either Achievable or Forbidden (witnessed by ImpossibilityWitness). |
| HomotopyGroup | https://uor.foundation/observable/HomotopyGroup | http://www.w3.org/2002/07/owl#Thing | | The k-th homotopy group πk(N(C), v) of the constraint nerve based at vertex v. |
| HigherMonodromy | https://uor.foundation/observable/HigherMonodromy | http://www.w3.org/2002/07/owl#Thing | | The image of πk(N(C)) → Aut(sitek) for k > 1. Generalises the MN_6 monodromy homomorphism. |
| WhiteheadProduct | https://uor.foundation/observable/WhiteheadProduct | http://www.w3.org/2002/07/owl#Thing | | The Whitehead product [α, β] ∈ πp+q−1 for α ∈ πp, β ∈ πq. |
| StratificationRecord | https://uor.foundation/observable/StratificationRecord | http://www.w3.org/2002/07/owl#Thing | | A record of the holonomy stratification of the moduli space at a given quantum level: the list of HolonomyStrata, their codimensions, and their relationship to the MorphospaceBoundary. |
| BaseMetric | https://uor.foundation/observable/BaseMetric | https://uor.foundation/observable/Observable | | Superclass for the six universal measurements. Every computation on the ring produces these six quantities: d_Δ, σ, J_k, β_k, χ, r. |
| GroundingObservable | https://uor.foundation/observable/GroundingObservable | https://uor.foundation/observable/Observable | | The grounding metric σ = pinned sites / total sites. Ranges from 0 (no sites pinned) to 1 (fully grounded). |
| EulerCharacteristicObservable | https://uor.foundation/observable/EulerCharacteristicObservable | https://uor.foundation/observable/Observable | | The Euler characteristic χ = Σ(−1)^k β_k of the constraint nerve. An integer-valued topological invariant. |