> The arithmetic performed by "-TEX’s expressions does not do much that
could not be done by TEX’s arithmetic operations \advance, \multiply, and
\divide, although there are some notable differences: Each factor is checked to
be in the allowed range, numbers must be less than 231 in absolute value, dimen-
sions or glue components must be less than 214 pt , mu , fil , etc. respectively.
The arithmetic operations are performed individually, except for ‘scaling’ opera-
tions (a multiplication immediately followed by a division) which are performed