If you look at older documents the \mathbb
characters appear different. For example they are sans serif. I don't know how I can use that set of characters instead of the current default.
If you are not sure what version I am talking about load the package fourier and then use \mathbb{C}
for example to see the difference. No other package beside fourier does that and I want to know how to do it with other packages.
Best Answer
The following is a hack that seems to do the work, it actually comes from the source of the
fourier
package.