For the people who love Calculus

Here is a joke for the people who love Calculus.

Consider two functions f(x) = e^x, g(x) = c and the unknown differential operator D. Now, consider the following scenario:

g(x) is running down the street in a great panic when he runs into f(x).

f(x) : Hey constant function c. What’s wrong?

g(x) : Oh, please help! I’m being chased by a differential operator!

f(x) : Don’t worry constant function c, for I am e to the x. You can differentiate me, integrate me, because I don't care!

So then f(x) walks around the corner to face D.

f(x) : Hey you! Yes, you differential operator scum! Why are you bullying constant function c?

D____: What are you talking about?

f(x) : Who are you anyway?

D____: I'm called d/dy

Thus the story ends tragically due to the fact that

d/dy (e^x) = 0