/**
 * Text Similarity Utilities
 *
 * Provides Jaccard similarity and related text comparison functions
 * for memory enrichment and contradiction detection.
 *
 * Phase 3 Organic Brain Feature
 */
/**
 * Tokenize text into a set of normalized words
 * Removes punctuation, lowercases, and filters short words
 */
export declare function tokenize(text: string): Set<string>;
/**
 * Calculate Jaccard similarity between two texts
 * Returns a value between 0 (completely different) and 1 (identical)
 *
 * Jaccard Index = |A ∩ B| / |A ∪ B|
 *
 * @param textA - First text to compare
 * @param textB - Second text to compare
 * @returns Similarity score between 0 and 1
 */
export declare function jaccardSimilarity(textA: string, textB: string): number;
/**
 * Extract key phrases/concepts from text
 * Used for topic comparison in contradiction detection
 *
 * Extracts:
 * - Quoted phrases ("like this")
 * - Backticked code/terms (`like_this`)
 * - Capitalized terms (LikeThis)
 *
 * @param text - Text to extract key phrases from
 * @returns Array of unique key phrases (lowercased)
 */
export declare function extractKeyPhrases(text: string): string[];
/**
 * Calculate word overlap between two texts
 * Returns the count of shared words
 *
 * @param textA - First text
 * @param textB - Second text
 * @returns Number of shared words
 */
export declare function wordOverlap(textA: string, textB: string): number;
/**
 * Check if two texts share significant content
 * Quick check before running full similarity calculation
 *
 * @param textA - First text
 * @param textB - Second text
 * @param minOverlap - Minimum word overlap required
 * @returns True if texts share at least minOverlap words
 */
export declare function hasSignificantOverlap(textA: string, textB: string, minOverlap?: number): boolean;
