eq { diff { hop { filter_eq { all_rows ; ship name ; ashantian } ; tonnage ( grt ) } ; hop { filter_eq { all_rows ; ship name ; manchester brigade } ; tonnage ( grt ) } } ; -1125 } = true
select the rows whose ship name record fuzzily matches to ashantian . take the tonnage  grt  record of this row . select the rows whose ship name record fuzzily matches to manchester brigade . take the tonnage  grt  record of this row . the second record is 1125 larger than the first record .