kelvin = proc (k: real) returns (real)
    return(k)
end kelvin

celsius = proc (k: real) returns (real)
    return(k - 273.15)
end celsius

rankine = proc (k: real) returns (real)
    return(k * 9./5.)
end rankine

fahrenheit = proc (k: real) returns (real)
    return(rankine(k) - 459.67)
end fahrenheit

conv = struct[letter: char, func: proctype (real) returns (real)]

convs = sequence[conv]$[
    conv${letter: 'K', func: kelvin},
    conv${letter: 'C', func: celsius},
    conv${letter: 'F', func: fahrenheit},
    conv${letter: 'R', func: rankine}
]

start_up = proc ()
    pi: stream := stream$primary_input()
    po: stream := stream$primary_output()

    stream$puts(po, "Enter temperature in Kelvin: ")
    k: real := real$parse(stream$getl(pi))

    for c: conv in sequence[conv]$elements(convs) do
        stream$putc(po, c.letter)
        stream$puts(po, "  ")
        stream$putl(po, f_form(c.func(k), 6, 2))
    end
end start_up