8. A system according to claim 7 wherein said data reduction means is adapted whereby w=b+(s-1)c.
8. A system according to claim 7 wherein said data reduction means is adapted whereby w=b+(s-1)c. 14. A system according to claim 8 wherein w=12, k=8, s=3, b=4, c=4, and a.sub.i =1/b.