Here is the case: This past Sabbath, at an ashkanazi synagogue, a sephardi comes to pray. This is the synagogue that he normally attends (there are about 20 within 1 sq mile). He prays with the ...
Some shuls have several minyanim back to back. If one arrives before the Torah reading of the 8:30 minyan and has finished davening before the Torah reading of the 9:30 minyan (to whose Kedusha one ...