Fib: Slide 2 of 6

<title>Recursive Definition</title>

<para>The Fibonacci series begins:
1 1 2 3 5 8 13... Each member of
the series, after the first two,
is the sum of the preceding two

<para>This can be implemented recursively
by calculating the preceding two
members of the series and returning
their sum:</para>

<src:fragment id="sub.fib.recursion">
&amp;fib($n-2) + &amp;fib($n-1);