Satyan L. Devadoss' first 6 lectures in The Great Courses' The Shape of Nature class on dvd gave my sister a significant challenge that led her to create this.

You can get the first 12 pages of Creating and Untangling Formulas by Ellen in pdf format (8.5mb) for free.

Quote from page 58:
     "Start advanced 17 last because it is the longest step, or step 19 because it creates twists."

Ellen's notes: The term "links" is the math term. An o or u describes an up arrow.
There's a sentence changed in the top part of page 6 if you buy it. It basically has the same meaning as before,
but is more clear. The sentence is changed to " mind that an over route..." and has "are the pairing partners here." added to the end.
Page 5 may also be updated from what is available for download and the first example is the worst.
This product has been finished for some time.
Matthew's note: My sister is very logical. :)

Purchase 60 page manual $14.25

Valid XHTML 1.1 Transitional