condition evaluation utility
- The standard way to escape a delimiter in a macro argument is to prepend a
zero-width space, like this:
Appending the zero-width space or enclosing the delimiter in double quotes
works too, but isn't recommended because these methods are less commonly
displays a summary of the commands.
- If escaping is forgotten, delimiters fall out of the macros. If that
leaves the macros empty, they may assume their default arguments. For
.Nm [ Ar expression Cm
where the square brackets are not set in bold face.