Exercise $4$: Appointment overlaps $($Reference: Textbook page $124)$

In a scheduling program, we want to check whether two appointments cverlap. For simplicity, appointments start at a full hour, and we use military time $($with hours D$-24).$ The following pseudocode describes an algorithm that determines whether the appointment with start time start$1$ and end time end $1$ overlaps with the appointment with start time start $2$ and end time end $2.$