text: from sympy import *
  
  
  # class Parameter():
  #     ''' Constant parameters. '''
  
  #     def __init__(self, **kwargs):
  #         self.__dict__ = kwargs
  
  
  # class Derivatives():
  #     pass
  
  
  # class Derivative():
  #     ''' '''
  
  
  # class Real():
  #     ''' '''
  
  
  # class Eq():
  #     pass
  
  
  # class Model():
  #     pass
  
  
  # def main():
  #     '''
  #     model FirstOrder
  #     parameter Real c=1 "Time constant";
  #     Real x (start=10) "An unknown";
  #     equation
  #     der(x) = -c*x "A first order differential equation";
  #     end FirstOrder;
  #     '''
  #     pass
  
  #     c = Parameter(name='c', value=1)
  #     x = Real(name='x', start=10)
  #     eq = Eq(name='A first order differential equation.',
  #             lhs=Derivative(state=x), rhs=-c*x)
  
  #     simulate(Eq)
  
  def main2():
  
      x = RealNumber()
      print(x)
      print("dklasfjd")
  