export declare type ReduceCallbackFunction = (previousValue: ReduceTo, currentValue: ArrOf, currentIndex: number, array: readonly ArrOf[]) => ReduceTo; export declare type ReduceArguments = [ReduceCallbackFunction, ReduceTo]; export declare function toReduceArguments(arrOp: (arr: readonly ArrOf[], ...params: Params) => ReduceTo, ...params: Params): ReduceArguments;