content: import numpy as np
  import matplotlib.pylab as plt
  from MulLayer import MulLayer
  
  class AddLayer:
          def __init__ (self):
                  pass
          
          def forward(self, x, y):
                  out = x + y
                  return out
  
          def backward(self, dout):
                  dx = dout * 1
                  dy = dout * 1
                  return dx,dy
  
  
  def test_add_layer():
          apple = 100
          apple_num = 2
          orange = 150
          orange_num = 3
          tax = 1.1
  
  
          mul_apple_layer = MulLayer()
          mul_orange_layer = MulLayer()
          add_apple_orange_layer = AddLayer()
          mul_tax_layer = MulLayer()
  
          apple_price = mul_apple_layer.forward( apple, apple_num)
          orange_price = mul_orange_layer.forward( orange, orange_num)
          all_price = add_apple_orange_layer.forward( apple_price, orange_price)
          price = mul_tax_layer.forward( all_price, tax)
  
  
          dprice = 1
          dall_price, dtax = mul_tax_layer.backward( dprice)
          dapple_price, dorange_price = add_apple_orange_layer.backward(dall_price)
          dorange, dorange_num = mul_orange_layer.backward(dorange_price)
          dapple, dapple_num = mul_apple_layer.backward( dapple_price)
  
          print("price=", price)
          print(dapple_num, dapple, dorange, dorange_num, dtax)
  
  
  