Given the problem below, is the attached solution for a ladder logic diagram correct? Consider control of the mixing process of two liquids $($ A and B$)$ shown in the scheme below. At first, on activating a hand switch $($HS$4,$ not shown in the diagram$),$ liquid A should be introduced $($VN$1).$ When the level reaches level LT$2,$ flow B is started $($VN$2).$ At the same time, motor $($MN$5)$ is started. When the level reaches LT$3,$ flow A and flow B are stopped. $20$ min after that, the motor is stopped, the discharge valve $($VN$3)$ is opened and the pump $($PN $4)$ is started. When the level reaches LT$1,$ the discharge valve $($VN$3)$ is closed and the pump $($PN$4)$ is stopped. At the same time indicator lamp $($LAMP$,$ not shown in diagram$)$ will be on for $20$min indicating that the process is finished.