[Rd] Line breaks in mathematical formulae in Rd files

[Daniel Elliott]

Hello,

I would like to implement the feature request described here:
https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=13287.  I think
this is a very worthwhile feature.

However, I need just a little push in the right direction.  When I
added either a new command or change the old one to use eqnarray as
proposed, the "\\" newline characters were not properly passed to
latex - even when I escaped them both with something like "\\\\".

What is happening behind the scenes that I am not understanding that
is disallowing me from making this small change so I can use "\\" with
an equation array?

Thank you, very much, for any assistance.

- dan