Gauss–Legendre algorithm

public class GaussLegendre {
  public static void main(String[] args) {
    double x1 = Double.MAX_VALUE;
    for (double a0 = 1,
            b0 = 1 / Math.sqrt(2),
            t0 = 1. / 4,
            p0 = 1,
            x0 = (a0 + b0) * (a0 + b0) / 4 / t0,
            a1,
            b1,
            t1,
            p1;
        Math.abs(x0 - x1) > Double.MIN_NORMAL;
        a1 = (a0 + b0) / 2, b1 = Math.sqrt(a0 * b0), t1 = t0 - p0 * (a0 - a1) * (a0 - a1),
            p1 = 2 * p0, a0 = a1, b0 = b1, t0 = t1, p0 = p1, x0 = x1,
            x1 = (a0 + b0) * (a0 + b0) / 4 / t0) {}
    System.out.println(x1);
  }
}