> with(linalg):
> A := inverse(matrix(4,4,[1,0,0,0,0,1,0,0,1,l,l^2,l^3,0,1,2*l,3*l^2]));
> 

                   [  1         0        0         0  ]
                   [                                  ]
                   [  0         1        0         0  ]
                   [                                  ]
                   [   3                 3            ]
                   [- ----    - 2/l     ----     - 1/l]
              A := [    2                 2           ]
                   [   l                 l            ]
                   [                                  ]
                   [  2        1          2       1   ]
                   [ ----     ----     - ----    ---- ]
                   [   3        2          3       2  ]
                   [  l        l          l       l   ]

# Im Folgenden fhrt das Computerprogramm die Multiplikation gem der
# Transformation (6.75) aus. Die Matrix in (6.71b,c) ist im
# Rechenprogramm mit  k  gekennzeichnet.
> k:=matrix(4,4,[0,0,0,0, 0,0,0,0, 0,0,4*l,6*l^2, 0,0,6*l^2,12*l^3]);

                         [0    0     0        0  ]
                         [                       ]
                         [0    0     0        0  ]
                         [                       ]
                    k := [                     2 ]
                         [0    0    4 l     6 l  ]
                         [                       ]
                         [             2        3]
                         [0    0    6 l     12 l ]

> p:=(EI)*(multiply(transpose(A),k,A));
> K:=(2*EI/l^3)*evalm(p*l^3/(2*EI));

                    [  12        6          12       6   ]
                    [ ----      ----     - ----     ---- ]
                    [   3         2          3        2  ]
                    [  l         l          l        l   ]
                    [                                    ]
                    [  6                    6            ]
                    [ ----      4/l      - ----     2/l  ]
                    [   2                    2           ]
                    [  l                    l            ]
            p := EI [                                    ]
                    [   12        6        12         6  ]
                    [- ----    - ----     ----     - ----]
                    [    3         2        3          2 ]
                    [   l         l        l          l  ]
                    [                                    ]
                    [  6                    6            ]
                    [ ----      2/l      - ----     4/l  ]
                    [   2                    2           ]
                    [  l                    l            ]


                         [ 6     3 l      -6     3 l ]
                         [                           ]
                         [          2              2 ]
                         [3 l    2 l     -3 l     l  ]
                    2 EI [                           ]
                         [-6     -3 l     6      -3 l]
                         [                           ]
                         [         2                2]
                         [3 l     l      -3 l    2 l ]
               K := ----------------------------------
                                     3
                                    l

# Dieses Ergebnis stimmt mit der Steifigkeitsmatrix in (6.69a,b) berein
# !
> 
