A simple Lightning Network transaction, how many transactions will be created on the main bitcoin chain? I guess is three transactions.
Alice create 2-to-2 multi-sig address AC
Alice put money in AC (first)
Bob put money in AC (second)
Alice create a refund transaction (third) both agree from AC send money to Alice and Bob, base on previous amount with lock-time.
case 1 before the lock-time:
Send a new transaction (fourth) to main chain, split the amount of two people. The thrid transaction with locktime will be ignored by miners.
case 2 debate, after lock-time
the third transaction will be put into the block by miners, refund all the money.