counting # bars since

[Carl Oberman <swtrans@xxxxxxxxxxx>]

lets say you have a formula that returns a value of "1" if true, "0" if
false.  for this example lets say you are testing for an inside bar.  so if
we have an inside bar, our formula gives us a "1."

QUESTION:

if i want to count the number of bars since an inside bar, is there a
counter formula?  here are the results id like to see.


BAR    INSIDE    COUNT

1      Y         1
2      N         2
3      N         3 
4      N         4
5      N         5 
6      N         6
7      Y         1
8      N         2
9      N         3
10     N         4
11     Y         1 
12     N         2

THANKS!