When three ate together and began to bentch individually (e.g., started 'Baruch Atah Hashem hazan et ha'olam'), at what point is the zimun obligation lost?

If three people ate together but each bentched individually (forgetting to do zimun), can they still perform zimun afterward?

3 opinions

If two of the three bentched individually but the third did not, can the two perform zimun with the third?

3 opinions

If the third person (who already bentched individually) subsequently performed zimun with a different group, can the original two still do zimun with him?

3 opinions

If one of the three left to the marketplace before Birkat HaMazon, can the remaining two call to him and perform zimun without his physical presence at the table?

3 opinions

If three people ate together but none of them knows the full Birkat HaMazon — only one knows the first blessing, one the second, and one the third — are they obligated in zimun, and may they each recite only the blessing they know?

4 opinions

Can two who bentched individually still join a different group of three for zimun?

1 opinions

In a group of ten where three forgot and bentched individually, may the remaining seven still perform zimun with God's name?

1 opinions