SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 3)
    Identifier ts
    Identifier metric
    Function nonNegativeDerivative (alias deriv) (children 1)
     ExpressionList (children 2)
      Identifier metric
      Identifier ts
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier nnd