Please see the beginning of 68a (K'she'chalah Rabbi Eliezer... could you please tell me what action he had taken earlier that put him into nidui (charem)? He was an immensely great scholar I understand and possible he only had an opinion different than the rabbis. But either case, how could he have isolated himself from his students by causing himself go into nidui because they could not now easily learn with him (? within 4 amos)?

Many thanks.

Yitzchak Coffer, Thornhill, Canada