Question 3. PN Modeling In this question, you are given a PN system and are asked to modify its structure to change its behavior. Submit your model with some description of its structure, and behavior. Also state your assumptions. Consider the PN system, shown below, that models two independent traffic lights at the crossing of two one- way roads. Each traffic light has three possible states: red (e.g., r), green (e.g., gl), and orange (e.g., ol) Each light proceeds through these states in a fixed order. A place of the PN corresponds to a state of the traffic light. Each transition represents a change of light's state, e.g., rgl models the event of light 1 turning from red (rl) to green (gl) Construct a single PN model to implement the following behavior (i) They have to work in such a way that there is always at least one red light; that is, at most one traffic light is green or orange (i rg1 rg2 or or2 go1 go2 01 02 Question 3. PN Modeling In this question, you are given a PN system and are asked to modify its structure to change its behavior. Submit your model with some description of its structure, and behavior. Also state your assumptions. Consider the PN system, shown below, that models two independent traffic lights at the crossing of two one- way roads. Each traffic light has three possible states: red (e.g., r), green (e.g., gl), and orange (e.g., ol) Each light proceeds through these states in a fixed order. A place of the PN corresponds to a state of the traffic light. Each transition represents a change of light's state, e.g., rgl models the event of light 1 turning from red (rl) to green (gl) Construct a single PN model to implement the following behavior (i) They have to work in such a way that there is always at least one red light; that is, at most one traffic light is green or orange (i rg1 rg2 or or2 go1 go2 01 02