factor

 A factor in a run-time expression can be any of the following:

      array-type-identifier array-constructor  
      constant-identifier
      constructor of schema type or of types containing
         schema components
      (expression) [[ :: type-identifier ]]
      function-identifier [[ actual-parameter-list ]]
      NOT factor
      numeric-constant
      real-constant
      record-type-identifier record-constructor
      schema discriminant
      [[ set-type-identifier ]] set-constructor
      string-constant
      variable

 A factor in a compile-time expression cannot include the following:

      call to user-defined functions
      call to EOF and EOLN predeclared functions
      constructor of schema type or of types containing
         schema components
      schema discriminant
      variable