/**
 * What a weak signal is measured *from*. The dual of `ProofSource` in
 * `constraints.ts`, and the reason this catalogue is bounded too: a signal SG
 * cannot observe is not a signal it can carry.
 *
 * - `timing`, when things happened, and the shape of the gaps
 * - `repetition`: how similar this interaction is to previous ones
 * - `interaction`, the presence and texture of human input
 * - `sequence`, the path taken, where no invariant forbids it
 * - `target`, what is being asked for, and how broadly
 * - `environment`, coarse client-side facts, never fingerprints
 */
export declare const SIGNAL_SOURCES: readonly ["timing", "repetition", "interaction", "sequence", "target", "environment"];
export type SignalSource = (typeof SIGNAL_SOURCES)[number];
/**
 * How much observing a signal is worth, in evidence mass.
 *
 * Deliberately three coarse levels rather than a per-signal number. A continuous
 * weight would imply calibration nobody has done (D36), and the ordering is the
 * only part that survives contact with real traffic anyway.
 */
export declare const SIGNAL_WEIGHTS: {
    /** Common in legitimate traffic too. Barely moves anything alone. */
    readonly faint: number;
    /** Unusual enough to be worth mass, inconclusive enough to need company. */
    readonly notable: number;
    /** Rarely innocent, but still measured rather than proven. */
    readonly pronounced: 0.5;
};
/**
 * The most mass all the weak signals of a single interaction may contribute.
 *
 * One weak observation, the least the trust model recognises. This is what
 * "never a standalone trigger" means numerically, and it is a stronger guarantee
 * than the wording alone: with the prior at `n = 2` and `developingAt` at `3`, an
 * interaction that trips *every* signal in the catalogue still leaves the entity
 * in the `unknown` stage, where the trust dimension asks for nothing (D40).
 *
 * So measurement cannot manufacture a treatment on its own. It takes repeated
 * interactions to accumulate past the stage boundary: which is exactly the
 * "meaningful in combination" the design notes ask for, combination over time
 * rather than a single well-instrumented request.
 */
export declare const SIGNAL_MASS_CAP: 0.5;
export type SignalWeight = keyof typeof SIGNAL_WEIGHTS;
export type WeakSignal = {
    readonly id: string;
    readonly source: SignalSource;
    readonly weight: SignalWeight;
    /** What is measured. Never a threshold, see the header. */
    readonly measures: string;
    /** Why a legitimate user might trigger it. The honest false-positive path. */
    readonly innocentCause: string;
    /**
     * Whether `behaviorFeatures` (D36) derives this server-side.
     *
     * `false` does not mean uncollectable: D51 added a collector for every entry in
     * this catalogue. It means the observation arrives from `./collect` or from the
     * host rather than being derived from the retained window.
     */
    readonly computed: boolean;
};
/**
 * The catalogue.
 *
 * The first four entries are drawn from the design notes §6B, which came from the
 * author's own scraping experience; the rest close the enumeration over
 * `SIGNAL_SOURCES`. `computed: true` marks the ones the anomaly feature space
 * (D36) derives from the retained window; the rest arrive from `./collect`, which
 * has a collector for each of them since D51.
 */
export declare const WEAK_SIGNALS: readonly WeakSignal[];
export declare function isWeakSignal(value: unknown): value is WeakSignal['id'];
/**
 * Negative evidence mass owed by a set of observed signals.
 *
 * Summed, not averaged: the notes are explicit that weak signals matter *in
 * combination*, and an average would make a second signal weaken the first.
 *
 * Capped at `SIGNAL_MASS_CAP`. A weak signal is measurement, and no pile of
 * measurements should outweigh what a host declared: nor should a catalogue that
 * grows over time quietly become more punitive per interaction than it was when
 * these thresholds were reasoned about.
 */
export declare function signalMass(observed: readonly string[], catalogue?: readonly WeakSignal[]): number;
/** The catalogue grouped by what it is measured from. For docs and coverage checks. */
export declare function signalsBySource(catalogue?: readonly WeakSignal[]): Record<SignalSource, readonly WeakSignal[]>;
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