[simmschi]

I have been in a similar situation and am sorry to hear about your cofounder.

From a personal perspective things should be pretty clear, no? Understand that your cofounder suddenly has a very different perspective on life and must change his priorities immediately. If he is going through chemo or surgery there will be long stretches where he will not be able to support you or the company. He may or may not come back. He may not recover. Cancer sucks.

From a company perspective things should also be clear? This is exactly why you have clause upon clause in your contracts, notarized, lawyered and signed. Life happens. People die, have accidents, quit, become sick. If you are unsure about your legal obligations get a lawyer.