#!/usr/bin/env python
# I've only been able to test this in version 2.3 so far

def evalfunction0(a):
    print "Call by eval - Success! arg =",a
def evalfunction3(a):
    def evalfunction1(a):
        string = "evalfunction0(a+1)"
        eval(string)
    def evalfunction2(a):
        string = "evalfunction1(a+1)"
        eval(string)
# uncomment the next line to make the PREVIOUS line work!
#        evalfunction1(-1)  
    string = "evalfunction2(a+1)"
    eval(string)

def callfunction0(a):
    print "Function call - Success! arg =",a
def callfunction3(a):
    def callfunction1(a):
        callfunction0(a+1)
    def callfunction2(a):
        callfunction1(a+1)
    callfunction2(a+1)

callfunction3(0)
evalfunction3(0)