Description of the illustration relational_properties.eps

{ column_definition
| virtual_column_definition
| period_definition
| { out_of_line_constraint | out_of_line_ref_constraint }
| supplemental_logging_props
}
  [, { column_definition
     | virtual_column_definition
     | period_definition
     | { out_of_line_constraint | out_of_line_ref_constraint }
     | supplemental_logging_props
     }
  ]...