(
  (\n ->
      # Use iterate to find the factorial of n.
      (&n&1&)		# initial value
      (\(&n&product&) ->
	  (& n 1 minus & product n times &)
	  product
	  ((n 0 equals) not)
	  select_ (\@@s->s)
      )
      iterate (\@@i->i)
  )
  # Name it 'factorial', and demonstrate.
  (\factorial ->
    {((5 factorial) show_integer) put; put_newline}
  )
)