Module vector 

Vector similarity and KNN operators.

Structs

CosineProbabilityOperator

Marks a vector operator (KNN, threshold, …) for probability-domain evidence conversion. Direct operator execution applies the uncalibrated (1 + score) / 2 bridge from cosine similarity in [-1, 1] to [0, 1] (Definition 7.1.2, Paper 3). At an engine fusion boundary the driver intercepts this marker and fits the Paper 5 query-pool likelihood-ratio transform instead; reusable calibrated models live in uqa_scoring::VectorCalibrationModel.

KNNOperator

KNN_k(q): top-k nearest neighbors by cosine similarity (Definition 3.1.3).

VectorSimilarityOperator

V_theta(q): returns documents with cosine similarity at least threshold (Definition 3.1.2). Returns an empty posting list when the field has no vector index registered.