fibonacci.erl

% Fibonacci numbers
% The Fibonacci sequence is given by 0, 1, 1, 2, 3, 5, … where subsequent values are given by adding the two previous values in the sequence.
%
% Give a recursive definition of the function fib/1 computing the Fibonacci numbers, and give a step-by-step evaluation of fib(4).
%
% Usage:
% lists:map(fun(X) -> fibonacci:fib(X) end, lists:seq(0, 10)).

-module(fibonacci).
-export([fib/1]).

fib(0) ->
    0;
fib(1) ->
    1;
fib(X) when X > 0 ->
    fib(X-1) + fib(X-2).