35. What determines when a corporation's existence commences?
36. Define estoppel.
37. Give an example of a corporation estoppel from denying its corporate existence.
38. Are third persons ever estopped from denying a corporation's legal existence? If so, give an example.
39. Is a corporation's charter a contract?
40. If a corporation's charter is a contract, who are the contracting parties?
41. At the present time can a corporation obtain an irrevocable charter?
42. Define de facto corporation.
43. Define de jure corporation.