Go-back-n, with an ACK loss and a packet loss

While refreshing some old theory, and solving couple of problems, one instance had me confused: "7 packages (0 to 6) with window size 3 are sent. Packet no. 2 ACK is lost the first time it is sent, and packet number 4 gets lost the first time it is sent"

I am aware that the window size will now encompass packets [2,3,4] since ACK2 has not been received a timeout would occur, and that same window will be re-sent. But Packet 4 is lost. I have tried to depict, what I think happens. Forgive my sketching skills:

For completeness. Lost acknowledge will not cause retransmission, because acknowledgement for next packet will implicitly ack the missing one.