atom K = prompt_number("Enter temperature in Kelvin >=0: ",{0,1e307})
printf(1,"    Kelvin: %5.2f\n   Celsius: %5.2f\nFahrenheit: %5.2f\n   Rankine: %5.2f\n\n",
                      {K,                 K-273.15,          K*1.8-459.67,      K*1.8})