Task: Code to Text
Input (English): and { only { filter_eq { all_rows ; year ; 1999 } } ; eq { hop { filter_eq { all_rows ; year ; 1999 } ; version } ; album version } } = true
Output (English): select the rows whose year record is equal to 1999 . there is only one such row in the table . the version record of this unqiue row is album version .