export declare const union: <T>(x: Set<T>, y: Set<T>) => Set<T>;
export declare const intersection: <T>(x: Set<T>, y: Set<T>) => Set<T>;
export declare const difference: <T>(x: Set<T>, y: Set<T>) => Set<T>;
export declare const isSuperset: <T>(x: Set<T>, y: Set<T>) => boolean;
export declare const isSubset: <T>(x: Set<T>, y: Set<T>) => boolean;
export declare const areEqual: <T>(x: Set<T>, y: Set<T>) => boolean;
