From mboxrd@z Thu Jan  1 00:00:00 1970
From: doug@cs.dartmouth.edu (Doug McIlroy)
Date: Tue, 04 Apr 2017 15:15:53 -0400
Subject: [TUHS] How did you ...
Message-ID: <201704041915.v34JFrX9085938@tahoe.cs.Dartmouth.EDU>

> [cpp] only became a separate program later than [v6]

It came into the manual in v8.