仮定法現在完了

Although Bill had a very strong will, if it had not been for his father's encouragement, he would probably still die in bed.
had とか had been とか would die とか、時制がこのままでいいか、直すならどう直すか。仮定法を考えるのに非常に優れた問題。問題文に無駄な部分がない。
http://www5c.biglobe.ne.jp/~jesazuma/diary113.htm#320