//  Electrical quantities classes:  Power  
//  -----------------------------
                                                package electric;
 public class Epower {
    double value;

 public Epower(double watts) {value =  watts;}
 public Epower(Epower x)     {value =  x.value;}
 public Epower()             {value =  0;}

//  Arithmetic operations (additive pattern)
//  ---------------------

 public Epower  addSet(Epower rs) {value += rs.value;  return this;}
 public Epower  subSet(Epower rs) {value -= rs.value;  return this;}
 public Epower  mpySet(double rs) {value *= rs;        return this;}
 public Epower  divSet(double rs) {value /= rs;        return this;}
 public Epower  modSet(double rs) {value %= rs;        return this;}
 public Epower  modSet(Epower rs) {value %= rs.value;  return this;}

 public Epower  minus()           {return new Epower(-value);}
 public double div(Epower rs)     {return value / rs.value;}

 public Epower  add(Epower rs) {return new Epower(this).addSet(rs);}
 public Epower  sub(Epower rs) {return new Epower(this).subSet(rs);}
 public Epower  mpy(double rs) {return new Epower(this).mpySet(rs);}
 public Epower  div(double rs) {return new Epower(this).divSet(rs);}
 public Epower  mod(double rs) {return new Epower(this).modSet(rs);}
 public Epower  mod(Epower rs) {return new Epower(this).modSet(rs);}

//  Mixed class arithmetic
//  ----------------------

 public Epotential div(Ecurrent   i) {return new Epotential(value/i.value);}
 public Ecurrent   div(Epotential v) {return new Ecurrent(value/v.value);}

 public boolean equals     (Epower rs){return value == rs.value;}
 public boolean lessThan   (Epower rs){return value  < rs.value;}
 public boolean greaterThan(Epower rs){return value  > rs.value;}

 public String toString() {return value + " watts";}

}