implement does have a pole somewhere in the complex plane, you need to
write another method for Laurent expansion around that point.
-Now that all the ingrediences for @code{cos} have been set up, we need
+Now that all the ingredients for @code{cos} have been set up, we need
to tell the system about it. This is done by a macro and we are not
going to descibe how it expands, please consult your preprocessor if you
are curious: