Stabiliti valoarea de adevar a propozitiilor : a) 17 apartine {8,10,15,17,20} b) {2,7,10,14,16,5} U ( spre stanga) {2,4,5,7} c) 8 nu apartine {n/n apartine N ,n = 2 ori a ,a Apartine N d) {1,3,10) U (Spre stanga) {0,1,2,...,12,13}