Order of operations in the operator splitting scheme showing the evolution of the N-body, hydro, and particle subsystems throughout one iteration step. Single-line arrows mean that the originating object is used in the calculation of the destination. Double lines indicated the evolution of one of the subsystems from the initial state (ellipse) over intermediate states (parallelogram) to the final state (round shape). Each rectangle with rounded corners is a computation of an intermediate quantity using the state of the subsystem to which it is connected. The rectangles with bars on the sides indicate an operation that changes the state of a system. The variables that were changed by an operation are indicated in boldface in the intermediate states.