> read("/afs/eos.ncsu.edu/users/k/kaltofen/www/courses/LinAlgebra/Maple/
> refpkg/Src/myinverse.mpl");
> A := matrix(3,3,[2,0,1,0,4,5,7,8,9]);

                               [2    0    1]
                               [           ]
                          A := [0    4    5]
                               [           ]
                               [7    8    9]

> printlevel:=5:
> refpkg['myinverse'](A);
{--> enter refpkg[myinverse], args = A

                               [2    0    1]
                               [           ]
                         AA := [0    4    5]
                               [           ]
                               [7    8    9]


                                n := 3


             Ainv := array(identity, 1 .. 3, 1 .. 3, [])


                  Elem step: mult row , 1,  by , 1/2


                   [1    0    1/2]      [1/2    0    0]
                   [             ]      [             ]
              AA=, [0    4     5 ], T=, [ 0     1    0]
                   [             ]      [             ]
                   [7    8     9 ]      [ 0     0    1]


           Elem step: add , 0,  times row , 1,  to row , 2


                   [1    0    1/2]      [1/2    0    0]
                   [             ]      [             ]
              AA=, [0    4     5 ], T=, [ 0     1    0]
                   [             ]      [             ]
                   [7    8     9 ]      [ 0     0    1]


           Elem step: add , -7,  times row , 1,  to row , 3


                  [1    0    1/2 ]      [1/2     0    0]
                  [              ]      [              ]
             AA=, [0    4     5  ], T=, [ 0      1    0]
                  [              ]      [              ]
                  [0    8    11/2]      [-7/2    0    1]


                           Finished col , 1


                  Elem step: mult row , 2,  by , 1/4


                 [1    0    1/2 ]      [1/2      0     0]
                 [              ]      [                ]
            AA=, [0    1    5/4 ], T=, [ 0      1/4    0]
                 [              ]      [                ]
                 [0    8    11/2]      [-7/2     0     1]


           Elem step: add , 0,  times row , 2,  to row , 1


                 [1    0    1/2 ]      [1/2      0     0]
                 [              ]      [                ]
            AA=, [0    1    5/4 ], T=, [ 0      1/4    0]
                 [              ]      [                ]
                 [0    8    11/2]      [-7/2     0     1]


           Elem step: add , -8,  times row , 2,  to row , 3


                 [1    0    1/2 ]      [1/2      0     0]
                 [              ]      [                ]
            AA=, [0    1    5/4 ], T=, [ 0      1/4    0]
                 [              ]      [                ]
                 [0    0    -9/2]      [-7/2    -2     1]


                           Finished col , 2


                 Elem step: mult row , 3,  by , -2/9


                 [1    0    1/2]      [1/2     0      0  ]
                 [             ]      [                  ]
            AA=, [0    1    5/4], T=, [ 0     1/4     0  ]
                 [             ]      [                  ]
                 [0    0     1 ]      [7/9    4/9    -2/9]


          Elem step: add , -1/2,  times row , 3,  to row , 1


                [1    0     0 ]      [1/9    -2/9    1/9 ]
                [             ]      [                   ]
           AA=, [0    1    5/4], T=, [ 0     1/4      0  ]
                [             ]      [                   ]
                [0    0     1 ]      [7/9    4/9     -2/9]


          Elem step: add , -5/4,  times row , 3,  to row , 2


                                    [1/9    -2/9    1/9 ]
                 [1    0    0]      [                   ]
                 [           ]      [-35    -11         ]
            AA=, [0    1    0], T=, [---    ---     5/18]
                 [           ]      [36     36          ]
                 [0    0    1]      [                   ]
                                    [7/9    4/9     -2/9]


                           Finished col , 3

<-- exit refpkg[myinverse] (now at top level) = array(1 .. 3, 1 ..
3,[(3, 2)=4/9,(2, 2)=-11/36,(3, 1)=7/9,(1, 3)=1/9,(3, 3)=-2/9,(1,
2)=-2/9,(2, 3)=5/18,(1, 1)=1/9,(2, 1)=-35/36])}

                        [1/9    -2/9    1/9 ]
                        [                   ]
                        [-35    -11         ]
                        [---    ---     5/18]
                        [36     36          ]
                        [                   ]
                        [7/9    4/9     -2/9]

>