What do you think Vito would have thought about Michael killing Fredo? Do you think it would have happened if he had been alive?

Edit* I'm not asking whether or not Michael would have waited for Vito to die before having Fredo killed. This is strictly "What Vito would have thought about one of his son's killing/wanting to kill the other.. and do you think he would have ever let it happen, whether Fredo tried to have Mike set up or not.

Note that Michael IS still the acting Boss.