[Rd] history of objects() and ls()

[Ben Bolker]

  I found out today (maybe I had known sometime before??) that objects()
is a synonym for ls().  I'm curious about the history, which seems to go
at least back to the beginning of R.  It's been thus since SVN revision
2 (Sep 1997) ...

svn cat https://svn.r-project.org/R/trunk/src/library/base/R/attach@2 |
grep objects

  I had a quick look at the Becker & Chambers brown book (1984) and
Becker and Wilks blue book (1988) on Google books and could find ls but
not objects() ... ?

  Anyone happen to know?

 cheers
   Ben Bolker