function log1pSeries( x ) {
	var mMult = -x;
	var mProd = -1.0;
	var k = 0;

	return next;

	/**
	* Calculate the next term of the series.
	*
	* @private
	* @returns {number} series expansion term
	*/
	function next() {
		mProd *= mMult;
		k += 1;
		return mProd / k;
	}
}
Creates a function to evaluate a Taylor series expansion `pow(-1, k-1) * pow(x, k) / k` for `ln(1 + x)`.

@private
@param {number} x - the value at which to evaluate the series
@returns {Function} series function