title: RecursionError: maximum recursion depth exceeded
body: <p>I'm working on building a python script to solve Riemann's Paradox. The idea is to take an inputted number, and add or subtract 1/2,1/3,1/4,1/5... to/from 1 until you have the inputted number. I'm running into the Recursion Error as a result of calling back to my comparison and adding/subtracting classes every time a comparison is made.</p>
  
  <p>My code is as follows:</p>
  
  <pre><code>import math
  #declare values of variables before they are referenced
  goal = float(input("What number are you trying to achieve?"))
  current_number = float(1)
  negatives = (2)
  positives = (3)
  #-----------------------------------------------------
  def add(goal,current_number,positives,negatives): #define the add operation for when the current number is less than the goal
      current_number = current_number+(1/positives) #add current fraction to the current number
      positives = positives+2 #Set the next additional fraction
      comparison(goal,current_number,positives,negatives) #go to comparision of the current number to the goal
  
  def subtract(goal,current_number,positives,negatives): #define the subtract operation for when the current number is greater than the goal
      current_number = current_number-(1/negatives) #subtract current fraction from the current number
      negatives = negatives+2 #set the next subtractional fraction
      comparison(goal,current_number,positives,negatives) #go to comparision of the current number to the goal
  
  def comparison(goal,current_number,positives,negatives): #define comparison between the current number to the goal
      if current_number &lt; goal:
          add(goal,current_number,positives,negatives) #if the current number is less than the goal, go to add the next fraction to it
      if current_number &gt; goal:
          subtract(goal,current_number,positives,negatives) #if the current number is greater than the goal, do to subtract the next fraction from it
      if current_number == goal:
          print("The equation for your number is 1+1/3...")
          print("+1/",positives)
          print("...-1/2...")
          print("-1/",negatives)
          #if the current number is equal to the goal, print the results
  
  comparison(goal,current_number,positives,negatives) #do the comparison between the current number and the goal
  </code></pre>
  
  <p>I'm wondering what I can do to solve this problem.</p>