I was in Saarbrueecken to perticipate my friend's Polterabend. When I took my breakfast on Satutday, I met an old friend, Tom, totally unexpected. Since he now lives in US. He just visited a week here. I just talked about an article I am going to write (this one), then it turns out that he is also reading Gilbert Strang's Introduction to Linear Algebra. What a coincidence. That reminds me that the end of last year. I was in Yokohama and met an old friend from Germany. The meeting is not so coincident since there was a big event related with my job and he also worked in the area. But again, he was also reading the same book. Murakami wrote some about Jazz's coincidence in his 'Tokyo Kitansyu (Strange stories in Tokyo)'. It is really such things happens sometimes.
Pairs of AB=-BA matrix.
2 months ago