The record selection expression (RSE) is used in many statements
       to specify a set of records, called a record stream. The format
       is:

           [FIRST n]
           [       ] [context-variable-1 IN]    rse-source-1
           [  ALL  ]

             [CROSS [context-variable-2 IN] rse-source-2 [OVER field-name-1]

         [WITH Boolean-expression]  [REDUCED to reduce-key[,...]]

         [SORTED BY {sort-key} [,...]]]

       The format for rse-source is:

            { remote-domain-name                                            }
            { rdb-relation-name                                             }
            { rdb-domain-name                                               }
            { rms-domain-name                                               }
            { collection-name                                               }
            { list                                                          }
            {                                                               }
            { dbms-record-name   [ { MEMBER }                            ]  }
            {                    [ { OWNER  } [OF] [context-var.set-name]]  }
            { dbms-domain-name   [ { WITHIN }                            ]  }