Unfortunately a small error crept into this file in the release last
week. calc.dtx has been updated on ftp.tex.ac.uk. Other ctan sites and
mirrors will update in due course.

If you have this version of calc:

          [1998/06/07 v4.1a Infix arithmetic (KKT,FJ)]

Please obtain a new calc.dtx from
which should have the following version info:

  [1998/07/07 v4.1b Infix arithmetic (KKT,FJ)]

and then regenerate calc.sty by running tex on tools.ins.

Sorry for this inconvenience and special apologies to
Kresten Krab Thorup and Frank Jensen who were responsible for this
package, but not responsible for introducing this bug.

David Carlisle
LaTeX3 Project