On page 233 an expression for the exterior derivative operator is provided in coordinate terms, and involves antisymmetrization brackets. The expression for antisymmetrization brackets containing 3 terms is given explicitly on page 214. Combining these and applying them to d

F (using the shorthand notation

) should yield:

The expression for d*

F is similar.

The above factor of 1/3 seems to have been left out of Robin's solution.In the derived equations, all instances of "

" should be changed to "

" to correct this.

(Note that there are 6 terms in the expression on p.214, but the negative ones are just doubles of the positive ones due to

F being antisymmetric, i.e.

...hence the factor of 3 here, rather than 6.)