MODE BR = LONG LONG REAL;
MODE POS = STRUCT(BR x, y, b);
BR pi = long long pi;
PROC (BR)BR lsrt = long long sqrt, ltan = long long tan,
   lln = long long ln, lexp = long long exp,
   lsin = long long sin, lcos = long long cos,
   latan = long long atan;
PROC st = (POS xs, BR d)POS: (
  BR x = x OF xs, y = y OF xs, b = b OF xs;
  BOOL o = b > pi/2;
  BR a = (o|pi - b|-b);
  BR cenx = x + y*ltan(b), l = lln(ltan(a/2 + pi/4));
  BR nl = (o|l-d|l+d), na = 2*latan(lexp(nl)) - pi/2;
  BR r = lsrt(y*y + (BR dx = cenx - x; dx*dx));
  BR nx = cenx + r*lsin(na), ny = r*lcos(na);
  BR pnb = (o|pi - na|-na), tnb = pnb + pi/2, nb = (tnb > 1.5*pi|tnb-2*pi|tnb);
  (nx, ny, nb));
PROC tv = (BR d)BR: (POS p := (0, 1, 0.1); TO 5 DO p := st(p, d) OD; x OF p);
(BR ela := 2.89, elb := 2.9, va := tv(lln(ela)), vb := tv(lln(elb));
 TO 300 DO BR la = -va/(vb-va), nel = ela + la*(elb - ela);
 BR nv = tv(lln(nel));
 BOOL o = va < vb, p = 0 < nv;
 IF o AND p OR NOT o AND NOT p THEN
     elb := nel; vb := nv ELSE ela := nel; va := nv FI OD;
 print((ela, newline, long long log(elb - ela), newline,
    1 - ela*(3 - ela*ela*ela*(3 - ela))))
 )