[Groff] Nesting macro calls in mdoc

[Colin Watson]

I've got a man page here, written in mdoc, which seems to nest macros
correctly according to the documentation but generates an error. Can
anyone shed any light on it? The line in question is:

  .Ic Sq \&? .

... which should print the three characters `?' in a literal font
followed by a dot. However, it produces this error message:

  Usage: .Ic interactive_command ... (#102)

Is it not possible to call quoting macros like Sq from other parsed
macros? Is the punctuation they generate confusing matters? The problem
doesn't seem to be unique to either .Ic or .Sq, so I'm wondering if I've
missed something much more fundamental in groff_mdoc(7).

Thanks,

-- 
Colin Watson                                  address@hidden