void setup() {
  // put your setup code here, to run once:
  pinMode(5, OUTPUT); //red TL 1
  pinMode(6, OUTPUT); //yellow TL 1
  pinMode(7, OUTPUT); //green TL 1
  pinMode(8, OUTPUT); //red TL 2
  pinMode(9, OUTPUT); //yellow TL 2
  pinMode(10, OUTPUT); //green TL 2
}

void loop() {
  // put your main code here, to run repeatedly:
  //PART 1 : IF TL 1 IS RED THEN TL 2 IS GREEN
  digitalWrite(5, HIGH); //TL 1 is RED
  digitalWrite(10, HIGH); //TL 2 is GREEN
  delay(5000);
  digitalWrite(5, LOW); //OFF TL 1
  digitalWrite(10, LOW); //OFF TL 2

  //PART 4 : IF TL 2 IS YELLOW THEN TL 1 IS RED
  digitalWrite(5, HIGH); //TL 1 is RED
  digitalWrite(9, HIGH); //TL 2 is YELLOW
  delay(5000);
  digitalWrite(5, LOW); //OFF TL 1
  digitalWrite(9, LOW); //OFF TL 2
  
  //PART 2 : IF TL 1 IS GREEN THEN TL 2 IS RED
  digitalWrite(7, HIGH); //TL 1 is GREEN
  digitalWrite(8, HIGH); //TL 2 is RED
  delay(5000);
  digitalWrite(7, LOW); //OFF TL 1
  digitalWrite(8, LOW); //OFF TL 2

  //PART 3 : IF TL 1 IS YELLOW THEN TL 2 IS RED
  digitalWrite(6, HIGH); //TL 1 is YELLOW
  digitalWrite(8, HIGH); //TL 2 is RED
  delay(5000);
  digitalWrite(6, LOW); //OFF TL 1
  digitalWrite(8, LOW); //OFF TL 2

}