Expected use case not caught by edit distance algorithm

[Sudesh-Prakash-Singh]

The following use case was not caught by surf in edit distance 2.

BIREN DUTTA -> BI DU REN TA
BIREN DATTA -> BI DATA REN

Expected: should show up in edit distance 2
Actual: doesn't show up

Tripura worksheet attached.
tripura_ws.csv.zip
attached.

[Sudesh-Prakash-Singh]

Another test case:

DASARATHA DEB -> ARTA DAS DEB
DASHARATH DEB -> DAS DEB RT

[hangal]

I find it works on a sample test case with these lines:

--
"Cand1","Candidate_Type","District_Name","comments","Position","Sex","Constituency_No","poll_no","Assembly_No","Constituency_Name","DelimID","Party","Year","Sub_Region","State_Name","Votes1","ID","Age"
"BIREN DUTTA","","","","1","M","35","0","9","GANGATH","3","BJP","1998","","Himachal_Pradesh","18771","4200","1"
"BIREN DATTA","","","","1","M","35","0","9","GANGATH","3","BJP","1998","","Himachal_Pradesh","18771","4209","2"
"DASARATHA DEB","GEN","MANDI","","6","M","33","0","12","MANDI","4","CPI","2012","BEAS RIVER REGION","Himachal_Pradesh","1468","3837","3"
"DASHARATH DEB","GEN","MANDI","","6","M","33","0","12","MANDI","4","CPI","2012","BEAS RIVER REGION","Himachal_Pradesh","1468","3839","4"