#print
A very powerful tool is to use pairs of addresses
which include searches.  For example, to print
all lines from the present line to the next line
containing "stop", say
  .,/stop/p
(remember that "." is the present line).  In this
directory is a file "outline".  Find the line that
begins "B.3.i".  Note that this line, and the next
few lines, should begin "A..." for consistency.
(Print the whole file to see what's wrong).
Change all lines from this line to
the line beginning "B.3.v" to begin "A.3".
Then rewrite the file and type "ready".
#create Ref
First section
A.1.i    Introduction
A.1.ii   Definitions
Second section
A.2.i    Scope
A.2.ii   Date effective
A.2.iii  Who covered
Third section
A.3.i    Governing committee
A.3.ii   Chairman's election
A.3.iii  Board terms
A.3.iv   Board elections
A.3.v    Removal procedure
Fourth section
A.4.i    Meetings
A.4.ii   Place of meeting
A.4.iii  Frequency of meetings
Fifth section
A.5.i    Record keeping
A.5.ii   Corresponding secretary
A.5.iii  Recording secretary
A.5.iv   Financial records
#create outline
First section
A.1.i    Introduction
A.1.ii   Definitions
Second section
A.2.i    Scope
A.2.ii   Date effective
A.2.iii  Who covered
Third section
B.3.i    Governing committee
B.3.ii   Chairman's election
B.3.iii  Board terms
B.3.iv   Board elections
B.3.v    Removal procedure
Fourth section
A.4.i    Meetings
A.4.ii   Place of meeting
A.4.iii  Frequency of meetings
Fifth section
A.5.i    Record keeping
A.5.ii   Corresponding secretary
A.5.iii  Recording secretary
A.5.iv   Financial records
#user
#cmp outline Ref
#succeed
You got it right: I hope you found that the easiest
way to change the file would be with the commands
 /B.3.i/p
 .,/B.3.v/s/B/A/
or some such series.
#log
#next
52.1b 10