QUESTION 12 & 13 DISCRETE MATHEMATICS. HELP

12. Consider the following argument. All breads by Gardenia are delicious. The shop sells breads by Gardenia. Therefore the shop sells delicious bread. By letting " D(x)=x is delicious", " G(x)=x is by Gardenia" and " S(x)= The shop sells x ", use rules of inference to show that the premises lead to the conclusion where the universe of discourse is the set of all breads. [10 marks] 13. Show that if A and B are sets, then AB=AB (a) by showing each side is a subset of the other side. [13 marks] (b) using set builder notation and logical equivalences laws. [9 marks] (c) using a membership table