There's a back story. The paper appears in the proceedings of a
conference held in London in 1973, a few months after the advent of
pipes. While preparing the presentation, Ken was inspired to invent
and install the pipe operator. His talk wouldn't have been nearly as
compelling had it been expressed in the original pipeline syntax (for
which I take the blame).
References to eqn (v5), bc (v6), and ratfor (v7) obviously postdate
the London conference. Ken must have edited--or re-created--the
transcript for the proceedings sometime after v6 (May, 1975).
Bibliographic citations are missing. Can they be resurrected?
Reference 137, about Unix itself, probably refers to a
presentation by Ken and Dennis at SOSP in January1973. Alas, only an
abstract of the talk appears in the conference proceedings. But the
abstract does contain the potent and often-repeated sentence, "It
offers a number of features seldom found even in larger operating
systems, including ... inter-process IO ..." The talk--in Yorktown
Heights--was memorable, and so was a ride to the same place in Ken's
'vette. (I can't recall whether the two happened on the same
occasion.)
Given that the talk at SOSP preceded the talk in London, and that the
Unix manual was widely distributed by (1976) when the revised London
talk was printed, the claim that "The Unix command language" was the
first publication of Unix seems hyperbolic. In no way, though, does
this detract from the inherent interest of the paper.
Doug