The SAS System                           1

                                  A

                            3         0         2
                            1         1         5


                                  B

                                 2        -1
                                 0         1
                                 7         3


                                  C

                                20         3
                                37        15


                                c1        c2

                                20         3
                                37        15

                            The SAS System                           2

                           Obs    C1    C2

                            1     20     3
                            2     37    15