def test_function_series3():
 class mytanh(Function, ):
  def fdiff(self, argindex=1):
   return (1 - (mytanh(self.args[0]) ** 2))
  @classmethod
  def eval(cls, arg):
   arg = sympify(arg)
   if (arg == 0):
    return sympify(0)
 e = tanh(x)
 f = mytanh(x)
 assert (tanh(x).series(x, 0, 6) == mytanh(x).series(x, 0, 6))

def test_function_series3 ( ) : class mytanh ( Function , ) : def fdiff ( self , argindex = 1 ) : return ( 1 - ( mytanh ( self . args [ 0 ] ) ** 2 ) ) @ classmethod def eval ( cls , arg ) : arg = sympify ( arg ) if ( arg == 0 ) : return sympify ( 0 ) e = tanh ( x ) f = mytanh ( x ) assert ( tanh ( x ) . series ( x , 0 , 6 ) == mytanh ( x ) . series ( x , 0 , 6 ) )
test our easy "tanh" function .