Formal power series extend the notion of a power series by removing the requirement for convergance[?]. Thus they have the same form as a power serries, but a more abstract interpretation which can be applied more generally.
... Friedrich Rosenkranz (April 23, 1805 - July 14, 1879), German philosopher, was born at Magdeburg.
He read philosophy at Berlin, Halle and Heidelberg, devoting himself ...