/** const a = NaN; a !== a; // true */
export declare const isBothNaN: (a: unknown, b: unknown) => boolean;
/** Returns if v1 equal to v2 (compares by valueOf);
 * @tutorial Features:
 * * null NotEqual undefined
 * * compares by valueOf
 * * checks if both NaN
 * */
export default function isEqual(v1: unknown, v2: unknown): boolean;