function reducer( arrays, dims, options, clbk, thisArg ) {
		var nargs = arguments.length;
		if ( nargs < 4 ) {
			return reduce( fcn, arrays, dims, options );
		}
		if ( nargs === 4 ) {
			return reduce( fcn, arrays, dims, options, clbk );
		}
		return reduce( fcn, arrays, dims, options, clbk, thisArg );
	}
Performs a reduction over a list of specified dimensions in an input ndarray via a one-dimensional strided array reduction function according to a callback function and assigns results to a provided output ndarray.

@private
@param {ArrayLikeObject<Object>} arrays - array-like object containing ndarrays
@param {IntegerArray} dims - list of dimensions over which to perform a reduction
@param {Options} [options] - function options
@param {Function} clbk - callback function
@param {thisArg} [thisArg] - callback execution context
@returns {void}