Answer Exercise 7, replacing each occurrence of ⋂ by ⋃.
Exercise 7
Let R1, R2 be relations on a set A.
(a) Prove or disprove that R1, R2 reflexive ⇒ R1 ⋂ R2 reflexive,
(b) Answer part (a) when each occurrence of "reflexive" is replaced by
(i) Symmetric;
(ii) Antisymmetric; and
(iii) Transitive.