R1 = (a, b.∈ r2, the "greater than" relation, r2 = a ≥ b, the "greater than or equal to" relation, r3 = (a, b.∈ r2, the "less than" relation, r4 = a ≤ b, the "less than or equal to" relation, r5 = a = b, the "equal to" relation, r6 = (a, b.
Answers (1)