> cdj schrieb:

> > Wow - am I the only one who thought that one helpful answer to the

> > question would be: $\mathbb{i}$ (using the amsfonts package) ?

> There is no such symbol in the AMS fonts.

> > (I don't have a TeX distro in front of me, but I _think_ that makes

> > the i-of-imaginary-numbers)

> The imaginary unit should simply be upright: \mathrm{i}. No extra

> package is required. (However, I don't know whether this is actually

> the symbol obtained by typing <Esc>ii<Esc> in Mathematica.)

Mathematica's symbol for i is actually a double-struck (that is,

blackboard bold) _italic_ lowercase "i". On screen it doesn't look

very italic, but in print it does. There are a few such letters:

i, j, e, d, and D. There is also a full blackboard bold alphabet,

where the letters are not italic in shape.

I agree with Walter, though, in preferring \mathrm{i}.

Mike