# Exterior Derivative question

there is a section that starts from:

Define the exterior derivative by $Dt ≡ \frac{\partial}{\partial x} \wedge t$

First of all, what does this first part quoted mean, in relation to the previous parts?

I then want to know what the rest of the section is talking about.

-
Egads, what horrible notation. Wolfram Mathworld is okay as a reference, but it really isn't where you should be learning stuff from. Instead try one of the standard texts on differential topology: Madsen and Tornehave, Lee, or Morita. –  Willie Wong Jun 27 '12 at 8:54
If you want to learn differential form, I would recommend the book of Do Carmo "Differential Forms and Applications" –  Paul Jun 27 '12 at 10:40