I have a question about spacing in math mode. Suppose you have a document that contains many times the nabla symbol. I have read in different answers in this website that it is advisable to write
\newcommand{\grad}{\mathop{}\!\nabla}
in the preamble in order to improve the spacing for expressions like c\nabla_{X}X
. In other words, now the spacing rules for \nabla_{X}X
become the same as those for \sin(x)
. (Please correct me if I am wrong.) The same rule applies to the letter d when used in differentials as dx
or dy
.
I generally follow this advice, but now I am a bit confused. If I implement this spacing correction, what is then the rationale for not doing the same for an expression like cf(t)
, where now f
is a function of the variable t
, and c
a constant? What about cf
, again with f
a function and c
a constant?
What is the most logical approach I should follow?
\grad
to have the same spacing as\sin
use\mathop{\nabla}
the construction that you show makes it have the same space to the left but no space to the right. compare\grad x
and\sin x