THRESH
for (bsize = bot - top; bsize >= THRESH; bsize--) {
bsize, THRESH, starts, startw, curw, curs, top, bot);
if (bsize < THRESH)
if (fabsl(a) >= THRESH || fabsl(b) >= THRESH) {
if(u.extu_frach>=THRESH) { /* if |x| is close to 1 */