Help with a formula to compare columns for deduplication efforts

Sorry, my description title might not make that much sense. See attached. (none of those are real names/dobs, btw)

I want to put a formula in column "M" that basically says to look at column b and if those are the same (they are paired off that way) then compare column L. If column L is the same on both pairs, then I can basically ignore those records because all the information matches. If not, then I need to look at them individually to determine if it refers to the same person and then do the actual fixing in the main database system.

I created a unique id based on all the data in the columns that would need to be compared and put that id in column L. The program that gave me the information created the other ids and puts likely duplicates together in pairs.

So roughly, something like if B1=B2 and L1=L2 "ignore)
if B1=B2 and L1 (does not equal) L2 "compare"

Or something like that.

:(

AttachmentSize
example.xlsx11.32 KB

How

How about:

=IF(B1=B2,IF(L1=L2,"ignore","compare"),"error")