There can, of course, be no such failure when the plaintiff's unwillingness or refusal to perform the contract on his or her part is the cause of the defendant's non-performance.
These people had uremia, a disease due to the failure of the kidneys, and expressed their unbearable suffering and an unwillingness to burden their families any more.
There are several causes of functional incontinence including confusion, dementia, poor eyesight, mobility or dexterity, unwillingness to toilet because of depression or anxiety or inebriation due to alcohol.
Furthermore, the unyieldingly strict enforcement of statutory limitations and the application of the non-retroactive principle to these political crimes clearly show an unwillingness to prosecute.