CaterpillarAdder.py

def multiadder(n):
  if n == 1:
    return lambda t: t
  else:
    return lambda a: lambda b: multiadder(n-1)(a+b)

def multiadder2(n):
  if n == 1:
    def f(x):
        return x
    return f
  else:
    def f(a):
        def g(b):
            return multiadder2(n-1)(a+b)
        return g
    return f

print(multiadder(2)(1)(1))