Please help me with All-Reduce simple function

I am trying to implement a simple allreduce function.

- There are N nodes in the network total

- send_functions is a list of functions for sending the value to other N-1 nodes. 
  eg, send_function(val) to send the value

- receive_functions is also a list of functions for receiving the values 
  from other N-1 nodes. eg, receive_function(val) to receive a value. 

Here are the functions:

def AR(send_functions, receive_functions, value):
       # return the number
       return 0.0