Ohm's law states that the electric current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the three mathematical equations used to describe this relationship:

The term "abstraction" has the connotation of distilling the essence of something (from the Latin abstrahere, to draw off from). Let her student and disseminator B. L van der Waerden define it:

Eine Inschrift im Gewölbe des Eingangstores zur Plassenburg erinnert an einen Vielgeliebten. Es ist Markgraf Friedrich, der zusammen mit seiner Gattin Wilhelmine in Bayreuth ruht.