Handling Subscripts for A
The "matrix" A was recorded internally as an array.
Here are the array subscripts
written in matrix form.
0 1 2 | 3 4 5 | 6 7 8
9 10 11 | 12 13 14 | 15 16 17
18 19 20 | 21 22 23 | 24 25 26
------------------------------
27 28 29 | 30 31 32 | 33 34 35
36 37 38 | 39 40 41 | 42 43 44
45 46 47 | 48 49 50 | 51 52 53
------------------------------
54 55 56 | 57 58 59 | 60 61 62
63 64 65 | 66 67 68 | 69 70 71
72 73 74 | 75 76 77 | 78 79 80
In searching through A I needed to
generate row subscripts, eg,
27 28 29 30 31 32 33 34 35
column subscripts, eg,
5 14 23 32 41 50 59 68 77
and block subscripts, eg,
30 31 32 39 40 41 48 49 50
The first two were trivial.