{ measure_column [ { condition | expr } [, { condition | expr } ]... ]
| aggregate_function 
        { [ { condition | expr } [, { condition | expr } ]... ]
        | [ single_column_for_loop [, single_column_for_loop ]... ]
        | [ multi_column_for_loop ]
        }
| analytic_function
}

Note: The outside square brackets shown in bold are part of the syntax.
      In this case, they do not represent optionality.