>>>var = 0
>>>var += 1
>>>var
1

def increment(i)
	i += 1
	return i

i = increment(i) + increment(i)

class inc:
	def __init__(s,p):
		s.p = p
	def __pos__(s):
        s.p += 1
        return s.p
    def __add__(s,p):
        s.p += 1
        return s.p - 1
    def __repr__(s):
        return '%s' % s.p

i = inc(2) 
q = ++i
q == 3; i == 3
q = i + 1
q == 3; i == 4