I did not, of course, know at the time that the will in question had only been made this afternoon, and I will admit that, when I learnt that fact, I fell into a grievous error. 
My children as well, did not know when the will had been created.
mnli hypothesis: My children as well, did not know when the will had been created. premise: I did not, of course, know at the time that the will in question had only been made this afternoon, and I will admit that, when I learnt that fact, I fell into a grievous error. 