$)$ Outline the differences between $$always$$ and $$initial$$ constructs. $(3$M$,$ BL$2,$ CO$2,$ CO$3,$ CO$4)$ b$)$ An elevator in a five floor building has five buttons in it for representing $1$st$,2$nd floor and so on$.$ There is an elevator request button in each floor. Assume that the buttons inside the lift are connected to respective request in the floors. Note: Consider a display for indicating current position of the lift. Develop a digital model for the movement of the elevator when respective buttons are pressed. $(3$M$,$ BL$3,$ CO$2,$ CO$3,$ CO$4)$ c$)$ Develop a Verilog code to implement such circuit.