Thanks nostr:npub18yvpnchj7yaepjk8yz2pn66hfmmup505aqvx0lpyc3aree0g5fyq8clpz3

since Q2 answer is A

What I understand is that if

user A have payment channel opened with user B (channel X),

and user B also have payment channel opened with user C (channel Y)

A can now transfer to user C indirectly using B as the intermediary

but since the payment require 2 payment channel to interact with each other,

1, how are the two different wallet interact with each other? is there some sort of smart contract that calculate and store how much of transfer are there that is related to payment from other channel?

2. how does lightning network figure out if there is a path fro user A to find user C via user B?

3. how does user A know that user B isn't lying by actually paying user C less than what user A is asking him of? since user A doesn't have channel open with user C. does user A TRUST user B with the payment to user C in full?

are those 3 problems, solved and managed by the node? so the node is the brain of lightning network?

if it solved by node. how does it ensure that

1. the node will try to find the best path with the least fee?

2. the node remain honest in case of "paying on behalf of" case. to not underpaid others