title: create type. pls 00363 expression cannot be used as an assignment
body: <p>help me please to understand this error..
  May be i must do ud_mosh_dvig(x number, y number) and create type body after.</p>
  
  <pre><code>create or replace type CAR as object
  (
   mosh_dvig number,
   obiem_dvig number,
   color varchar2(20),
   type_form varchar2(20),
   massa number,
   num_peredach number,
   ud_mosh number,
   member function ud_mosh_dvig return number
  );
  
  create or replace type body CAR
  is
  member function ud_mosh_dvig return number
  as
  begin 
   self.ud_mosh:=self.mosh_dvig/self.massa;
   return self.ud_mosh;
  end ud_mosh_dvig;
  end;
  </code></pre>