resource raise_to_power()
   var x, y, z, u, v : real
   var i, j, k : int

   do read(x, y, i, j) != EOF ->
      z := x ** y;   write(x, "**", y, "=", z)
      k := i ** j;   write(i, "**", j, "=", k)
      u := i ** y;   write(i, "**", y, "=", u)
      v := x ** j;   write(x, "**", j, "=", v)
   od
end raise_to_power

/* ............... Example compile and run(s)

% sr -o powers powers.sr
% ./powers
2.5 3.7 3 4
2.50000 ** 3.70000 = 29.6741
3 ** 4 = 81
3 ** 3.70000 = 58.2571
2.50000 ** 4 = 39.0625
-2.0 3.0 3 -2
-2.00000 ** 3.00000 = -8.00000
RTS abort: file powers.sr, line 7:
   i**j with j<0
                                              */