1 10/17/84  reverse_after, rvaf
 2 
 3 Syntax as a command:  rvaf STRA STRB
 4 
 5 
 6 Syntax as an active function:  [rvaf STRA STRB]
 7 
 8 
 9 Function:  performs the same function as the after command/active
10 function, but in reverse order.
11 
12 
13 Notes:  The active function returns that part of STRA following the
14 last occurrence of STRB in STRA (after uses the first occurrence).  If
15 STRB occurs last in STRA or does not occur at all, a null string is
16 returned.
17    [reverse_after STRA STRB]
18 is the same as--
19    [reverse [before [reverse STRA] [reverse STRB]]]
20 when STRB appears in STRA.  It is a null string when STRB does not
21 appear in STRA.