operator: merged-matrix

    description:
        merged-matrix[opn, ..., op2, op1]
        merged-matrix[opn, ..., op2, op1] sp
        merge the operators into a single merged matrix
        
    examples:
        load matrices.sw
        merged-matrix[M2,M1]
            [ z1 ] = [  0   42  6   6  36  24  6   ] [ x1 ]
            [ z2 ]   [  9   32  14  2  24  32  8   ] [ x2 ]
            [ z3 ]   [  12  73  23  7  58  60  15  ] [ x3 ]
            [ z4 ]   [  0   63  9   9  54  36  9   ] [ x4 ]
            [ z5 ]   [  3   41  9   5  34  28  7   ] [ x5 ]
                                                     [ x6 ]
                                                     [ x7 ]

        -- specify the input kets of interest, here |x1>, |x2>, |x3>:
        merged-matrix[M2, M1] split |x1 x2 x3>
            [ z1 ] = [  0   42  6   ] [ x1 ]
            [ z2 ]   [  9   32  14  ] [ x2 ]
            [ z3 ]   [  12  73  23  ] [ x3 ]
            [ z4 ]   [  0   63  9   ]
            [ z5 ]   [  3   41  9   ]


    see also:
        matrix, naked-matrix