Ejemplo de hilos en java (repaso)

public class serie extends Thread
{

private double sup;
private double inf;
private double i;
private double suma=0;

serie(double a,double b)
{
inf=a;
sup=b;
System.out.println(inf);
System.out.println(sup);
}

public void run()
{
for(i=inf;i<=sup;i++)
{
suma=suma+i;
System.out.println("Hilo--> "+this.getName());
System.out.println(suma);
}
}


public static void main(String args[])
{
serie h1=new serie(2,5);
h1.setName("Uno");
serie h2=new serie(5,10);
h2.setName("Dos");
h1.start();
h2.start();

}

}