Congruence subgroup problem

memo

• http://wstein.org/edu/Fall2003/252/lectures/09-19-03/index.html

articles

• Raghunathan, M. S. “The Congruence Subgroup Problem.” Proceedings Mathematical Sciences 114, no. 4 (November 1, 2004): 299–308. doi:10.1007/BF02829437.
• Sheydvasser, Arseniy. “A Corrigendum to Unreasonable Slightness.” arXiv:1506.03769 [math], June 9, 2015. http://arxiv.org/abs/1506.03769.