thermometer c = new centigrade();
  thermometer f = new fahrenheit();
  
  displayer cd = new displayer("centigrade");
  displayer fd = new displayer("fahrenheit");
  
  prompter cp = new prompter("enter centigrade value");
  prompter fp = new prompter("enter fahrenheit value");
  
  show sc = new show(c,cd);
  show sf = new show(f,fd);
  
  update uc = new update(c,cp);
  update uf = new update(f,fp);
  

slide: Installing the objects