go =>
  println("Function: Use apply/n"),
  Fun = "fib",
  A = 10,
  % Convert F to an atom
  println(apply(to_atom(Fun),A)),
  nl,

  println("Predicate: use call/n"),
  Pred = "pyth",
  call(Pred.to_atom,3,4,Z),
  println(z=Z),

  % Pred2 is an atom so it can be used directly with call/n.
  Pred2 = pyth,
  call(Pred.to_atom,13,14,Z2),
  println(z2=Z2),

  nl.

% A function
fib(1) = 1.
fib(2) = 1.
fib(N) = fib(N-1) + fib(N-2).

% A predicate
pyth(X,Y,Z) =>
  Z = X**2 + Y**2.