BEGIN

    PROCEDURE OUTMATRIX(A, W); INTEGER ARRAY A; INTEGER W;
    BEGIN
        INTEGER I, J;
        INTEGER LA1, UA1;
        INTEGER LA2, UA2;

        LA1 := LOWERBOUND(A, 1); UA1 := UPPERBOUND(A, 1);
        LA2 := LOWERBOUND(A, 2); UA2 := UPPERBOUND(A, 2);

        FOR I := LA1 STEP 1 UNTIL UA1 DO
        BEGIN
            OUTTEXT("[");
            FOR J := LA2 STEP 1 UNTIL UA2 DO
            BEGIN
                IF NOT (J = LA2) THEN OUTCHAR(' ');
                OUTINT(A(I, J), W)
            END;
            OUTTEXT("]");
            OUTIMAGE
        END
    END OUTMATRIX;

    PROCEDURE KRONECKERPRODUCT(A, B, C); INTEGER ARRAY A, B, C;
    BEGIN
        INTEGER I, J, K, L, CI, CJ;
        INTEGER LA1, UA1;
        INTEGER LA2, UA2;
        INTEGER LB1, UB1;
        INTEGER LB2, UB2;

        LA1 := LOWERBOUND(A, 1); UA1 := UPPERBOUND(A, 1);
        LA2 := LOWERBOUND(A, 2); UA2 := UPPERBOUND(A, 2);
        LB1 := LOWERBOUND(B, 1); UB1 := UPPERBOUND(B, 1);
        LB2 := LOWERBOUND(B, 2); UB2 := UPPERBOUND(B, 2);

        CI := 1;
        FOR I := LA1 STEP 1 UNTIL UA1 DO
            FOR K := LB1 STEP 1 UNTIL UB1 DO
            BEGIN
                CJ := 1;
                FOR J := LA2 STEP 1 UNTIL UA2 DO
                    FOR L := LB2 STEP 1 UNTIL UB2 DO
                    BEGIN
                        C(CI, CJ) := A(I, J) * B(K, L);
                        CJ := CJ + 1
                    END;
                CI := CI + 1
            END
    END KRONECKERPRODUCT;

    ! --- EXAMPLE 1 --- ;
    BEGIN
        INTEGER ARRAY A(1:2, 1:2);
        INTEGER ARRAY B(1:2, 1:2);
        INTEGER ARRAY C(1:4, 1:4);


        ! {{1, 2}, {3, 4}} ;

        A(1, 1) := 1;
        A(1, 2) := 2;

        A(2, 1) := 3;
        A(2, 2) := 4;

        ! {{0, 5}, {6, 7}} ;

        B(1, 1) := 0;
        B(1, 2) := 5;

        B(2, 1) := 6;
        B(2, 2) := 7;

        OUTMATRIX(A, 2); OUTTEXT("   *"); OUTIMAGE;
        OUTMATRIX(B, 2); OUTTEXT("   ="); OUTIMAGE;

        KRONECKERPRODUCT(A, B, C);

        OUTMATRIX(C, 2); OUTIMAGE

        ! OUTPUT:

        ! [ 0  5  0 10]
        ! [ 6  7 12 14]
        ! [ 0 15  0 20]
        ! [18 21 24 28] ;

    END EXAMPLE 1;

    ! --- EXAMPLE 2 --- ;
    BEGIN
        INTEGER ARRAY X(1:3, 1:3);
        INTEGER ARRAY Y(1:3, 1:4);
        INTEGER ARRAY C(1:9, 1:12);

        ! {{0, 1, 0}, {1, 1, 1}, {0, 1, 0}} ;

        X(1,1) := 0;
        X(1,2) := 1;
        X(1,3) := 0;

        X(2,1) := 1;
        X(2,2) := 1;
        X(2,3) := 1;

        X(3,1) := 0;
        X(3,2) := 1;
        X(3,3) := 0;

       ! {{1, 1, 1, 1}, {1, 0, 0, 1}, {1, 1, 1, 1}} ;

        Y(1,1) := 1;
        Y(1,2) := 1;
        Y(1,3) := 1;
        Y(1,4) := 1;

        Y(2,1) := 1;
        Y(2,2) := 0;
        Y(2,3) := 0;
        Y(2,4) := 1;

        Y(3,1) := 1;
        Y(3,2) := 1;
        Y(3,3) := 1;
        Y(3,4) := 1;

        OUTIMAGE;

        OUTMATRIX(X, 1); OUTTEXT("   *"); OUTIMAGE;
        OUTMATRIX(Y, 1); OUTTEXT("   ="); OUTIMAGE;

        KRONECKERPRODUCT(X, Y, C);

        OUTMATRIX(C, 1); OUTIMAGE;

        ! OUTPUT:

        ! [0 0 0 0 1 1 1 1 0 0 0 0]
        ! [0 0 0 0 1 0 0 1 0 0 0 0]
        ! [0 0 0 0 1 1 1 1 0 0 0 0]
        ! [1 1 1 1 1 1 1 1 1 1 1 1]
        ! [1 0 0 1 1 0 0 1 1 0 0 1]
        ! [1 1 1 1 1 1 1 1 1 1 1 1]
        ! [0 0 0 0 1 1 1 1 0 0 0 0]
        ! [0 0 0 0 1 0 0 1 0 0 0 0]
        ! [0 0 0 0 1 1 1 1 0 0 0 0] ;

    END EXAMPLE 2;
END