[texhax] Cases for italic correction

[Philip TAYLOR]

Barbara Beeton wrote:

> unlike all other letters in the cm math italic
> font, the d has no built-in "overhang" spacing.
> i've never actually asked, but i think the
> reason for this is that knuth uses d only for
> indicating derivatives (as in "dx"), not for
> variables, and for that use, he prefers it to
> be directly adjacent to the variable involved,
> not separated by a small space.

But what of a second derivative ?  That would require d^2y/dx^2,
which will surely generate almost exactly the same inteference
as Michael asserts obtains in d^3 (but which Lars and I cannot see).

** Phil