ExerciseConsider these relations on the set of integers:R$1=\{($a$,$b$)|$a$<=$b$\}$R$2=\{($a$,$b$)|$a$>$b$\}$R$3=\{($a$,$b$)|$a$=$bora$=$b$\}$R$4=\{($a$,$b$)|$a$=$b$\}$R$5=\{($a$,$b$)|$a$=$b$+1\}$R$6=\{($a$,$b$)|$a$+$b$<=3\}$Which of these relations are reflexive?