Either the proof is incorrect or he/she set it up in a way to make it look extremely trivial. The way I saw the proof go is: to satisfy CAP, you need replicati

Either the proof is incorrect or he/she set it up in a way to make it look extremely trivial. The way I saw the proof go is: to satisfy CAP, you need replication, and you need high availability. To be consistent you need replication. But if you don’t have a reliable network, you don’t get reliable replication. Therefore you can’t be consistent. To me, this is a trivial result, and I’m not sure that this is what the CAP theorem intends to say? It would be better to do, as you say, assume that a system is CA, And prove why it can’t be partition tolerant. Saying “network is unreliable” isn’t a suitable jump in argument IMO.