less { hop { filter_eq { all_rows ; year ; 1963 } ; finish } ; hop { filter_eq { all_rows ; year ; 1971 } ; finish } } = true
select the rows whose year record fuzzily matches to 1963 . take the finish record of this row . select the rows whose year record fuzzily matches to 1971 . take the finish record of this row . the first record is less than the second record .