> with(linalg):
Warning, the protected names norm and trace have been redefined and
unprotected

> A := matrix(2,3);

                    A := array(1 .. 2, 1 .. 3, [])

> B := matrix(3,2);

                    B := array(1 .. 3, 1 .. 2, [])

> evalm(A);

                   [A[1, 1]    A[1, 2]    A[1, 3]]
                   [                             ]
                   [A[2, 1]    A[2, 2]    A[2, 3]]

> C := evalm(A &* B);

  C :=

        [A[1, 1] B[1, 1] + A[1, 2] B[2, 1] + A[1, 3] B[3, 1] ,

        A[1, 1] B[1, 2] + A[1, 2] B[2, 2] + A[1, 3] B[3, 2]]

        [A[2, 1] B[1, 1] + A[2, 2] B[2, 1] + A[2, 3] B[3, 1] ,

        A[2, 1] B[1, 2] + A[2, 2] B[2, 2] + A[2, 3] B[3, 2]]

> A1 := matrix(2,3,[-2,1,3,4,1,6]);

                               [-2    1    3]
                         A1 := [            ]
                               [ 4    1    6]

> B1 := matrix(3,2,[3,-2,2,4,1,-3]);

                                 [3    -2]
                                 [       ]
                           B1 := [2     4]
                                 [       ]
                                 [1    -3]

> evalm(A1 &* B1);

                             [-1     -1]
                             [         ]
                             [20    -22]

> evalm(B1 &* A1);

                          [-14     1     -3]
                          [                ]
                          [ 12     6     30]
                          [                ]
                          [-14    -2    -15]

> subs(x=0, 1/x);
Error, division by zero

> B2 := matrix(1,3);

                   B2 := array(1 .. 1, 1 .. 3, [])

> evalm(A &* B2);
Error, (in linalg[multiply]) non matching dimensions for vector/matrix
product

> C2 := matrix(2,1);

                   C2 := array(1 .. 2, 1 .. 1, [])

> R1 := evalm((A &* B) &* C2);

  R1 :=

        [(A[1, 1] B[1, 1] + A[1, 2] B[2, 1] + A[1, 3] B[3, 1])

        C2[1, 1] +

        (A[1, 1] B[1, 2] + A[1, 2] B[2, 2] + A[1, 3] B[3, 2])

        C2[2, 1]]

        [(A[2, 1] B[1, 1] + A[2, 2] B[2, 1] + A[2, 3] B[3, 1])

        C2[1, 1] +

        (A[2, 1] B[1, 2] + A[2, 2] B[2, 2] + A[2, 3] B[3, 2])

        C2[2, 1]]

> R2 := evalm(A &* (B &* C2));

  R2 :=

        [(A[1, 1] B[1, 1] + A[1, 2] B[2, 1] + A[1, 3] B[3, 1])

        C2[1, 1] +

        (A[1, 1] B[1, 2] + A[1, 2] B[2, 2] + A[1, 3] B[3, 2])

        C2[2, 1]]

        [(A[2, 1] B[1, 1] + A[2, 2] B[2, 1] + A[2, 3] B[3, 1])

        C2[1, 1] +

        (A[2, 1] B[1, 2] + A[2, 2] B[2, 2] + A[2, 3] B[3, 2])

        C2[2, 1]]

> equal(R1,R2);

                                 true

> ?fibonacci
> with(combinat);
Warning, the name fibonacci has been redefined

Warning, the protected name Chi has been redefined and unprotected


  [Chi, bell, binomial, cartprod, character, choose, composition,

        conjpart, decodepart, encodepart, fibonacci, firstpart,

        graycode, inttovec, lastpart, multinomial, nextpart, numbcomb,

        numbcomp, numbpart, numbperm, partition, permute, powerset,

        prevpart, randcomb, randpart, randperm, stirling1, stirling2,

        subsets, vectoint]

> for i from 0 to 10 do print(fibonacci(i)); od;

                                  0


                                  1


                                  1


                                  2


                                  3


                                  5


                                  8


                                  13


                                  21


                                  34


                                  55

> for i from 0 to 10 do print(fibonacci(-i)); od;

                                  0


                                  1


                                  -1


                                  2


                                  -3


                                  5


                                  -8


                                  13


                                 -21


                                  34


                                 -55

>