One day e^x was walking through the forest being his arrogant self; as usual, e^x was boasting to all the various functions he happened to walk by saying things like... "I'm e^x don't you wish you could be like me??? You can take my derivative as many times as you wish but I will always be e^x." Anyways e^x walks up to the number 5, who happens to be frantic and asks him what is wrong. 5 tells e^x there is a partial derivative operator going around and if he catches him that he will go to nothing. e^x in his cocky tone tells 5 not to worry, that he will take care of it. e^x sets out in search for the operator but instead is discovered by the operator him self not aware of whom this person is e^x introduces him self. It is then that the operator introduces him self stating, hi I'm dx/dy.