abstracted structures fixed

src/builtin_structures/fibonacci.py

@@ -33,6 +33,22 @@ def fib(n):
     return b
 
 
+def fib_rec(n):
+    '''
+    >>> fib_rec(2)
+    1
+    >>> fib_rec(5)
+    5
+    >>> fib_rec(7)
+    13
+    '''
+    if n < 3:
+        return 1
+    return fib_rec(n - 1) + fib_rec(n - 2)
+
+
+
+
 if __name__ == '__main__':
     import doctest
     doctest.testmod()