proc binSearch val . a[] res .
low = 1
high = len a[]
res = 0
while low <= high and res = 0
mid = (low + high) div 2
if a[mid] > val
high = mid - 1
elif a[mid] < val
low = mid + 1
else
res = mid
.
a[] = [ 2 4 6 8 9 ]
binSearch 8 a[] r
print r