SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 5)
    Literal Float64_nan (alias x)
    Function erf (children 1)
     ExpressionList (children 1)
      Identifier x
    Function erfc (children 1)
     ExpressionList (children 1)
      Identifier x
    Function lgamma (children 1)
     ExpressionList (children 1)
      Identifier x
    Function tgamma (children 1)
     ExpressionList (children 1)
      Identifier x