m4: Divnum

1 
1 10.3 Diversion numbers
1 ======================
1 
1 The current diversion is tracked by the builtin 'divnum':
1 
1  -- Builtin: divnum
1      Expands to the number of the current diversion.
1 
1      Initial divnum
1      =>Initial 0
1      divert(`1')
1      Diversion one: divnum
1      divert(`2')
1      Diversion two: divnum
1      ^D
1      =>
1      =>Diversion one: 1
1      =>
1      =>Diversion two: 2
1