Bob has recieved 50,200 satoshi from Alice and paid 50,100 satoshi to Chan, so he has an extra 100 satoshi in his channel balances from routing fees.
Bob has received 50,200 satoshi from Alice and paid 50,100 satoshi to Chan, so he has an extra 100 satoshi in his channel balances from routing fees.
Alice receives the secret and has settled the 50,200 satoshi HTLC. The secret can be used as a _receipt_ to prove that Dina got paid for that specific payment hash.