export declare const isFunction: (value: any) => value is (...args: any[]) => any;
export declare const isArray: (value: any) => value is any[];
export declare const isString: (value: any) => value is string;
export declare const isBoolean: (value: any) => value is boolean;
export declare const isNumber: (value: any) => value is number;
export declare const isNaN: (value: any) => any;