public static Celcius operator -(Celcius c, Kelvin k)
{
Celcius retorno = (c.GetGrados() - ((Celcius)k).GetGrados());
return(retorno);
}
public static Celcius operator -(Celcius c, Fahrenheit f)
{
Celcius retorno = (c.GetGrados() - ((Celcius)f).GetGrados());
return(retorno);
}