asserts that the dialogue subact in the tutorial session for student s at time t is equal to u. Mode(s, t, m!)
asserts that the dialogue mode in the tutorial session for student s at time t is equal to m. Finally, ModeSwitch(s, t) asserts that there was a switch in dialogue mode at time t for the tutoring session associated with student s. the mode in the previous time step was different from the mode in the current time step.