request. So the command:
/pattern/;/
finds the second line containing "pattern" after the current line.
Caveat: The commands `st' and `sr' are now both legal and have very
different meanings. This is because ed(1) extends POSIX to include the
old Berkeley syntax s[rgp]*.
(So should two slashes still be required in the case of the substitute
command, as SunOS ed does?)