q = startQuery(r, qstr, type):
    check for valid query (e.g. #tuples)
    T = type of signature (t,p,b,x)
    Sig = build query signature of type T
    use Sig to determine list of interesting pages
    q->pages = bit-string of interesting pages
if (q == NULL) fatal error
scanAndDisplayMatchingTuples(Query q):
    foreach PID in q->pages {
        Buf = get page PID
        scan Buf for real matches and display each
    }