not quite sure everyone understood the question i asked earlier about Nostr relays, because i WASN'T describing a scenario with no relay overlap.
rather, the scenario i was asking about was this:
John: i made a post. i talk to relays A and B.
Pete: i'm sharing John's post,. i talk to relays A, B and C.
Charles: i talk to relay C only. can i see John's post, since Pete is sharing it?