less { hop { filter_eq { all_rows ; family / families ; the swift family } ; original air date } ; hop { filter_eq { all_rows ; family / families ; the potter family } ; original air date } } = true
select the rows whose family  families record fuzzily matches to the swift family . take the original air date record of this row . select the rows whose family  families record fuzzily matches to the potter family . take the original air date record of this row . the first record is less than the second record .