User blog comment:QuasarBooster/Bashicu matrix version 4 in Python!/@comment-30846880-20191110043015/@comment-24923514-20191110045635

P進大好きbot pointed out that the logic I used for finding ancestors is wrong. I'll change the code tomorrow so that it finds ancestors correctly. Thanks for the BMS checker!

(Also, I coded matrices the way they're defined on the article, so for S=(0,0)(1,1)(2,0)(1,1) my code would also be 0, 0],[1, 1],[2, 0],[1, 1.)