"""
File: local4.py
Python allows local functions to be defined.

Local functions can have local functions
nested inside as well.

"""

def A(n):

   def B(y):
      nonlocal a 
      a = a + 1 
      return y + a

   def C(z) :

      def D(i) :
         b = B(i)
         c = B(b)
         return c

      a = 0    # not the one in A
      return D(z)

   a = 2*n
   x = C(7) 
   print("a = " + str(a))
   return x

r = A(2)
print ("r = " + str(r))