(C-B)uA= {0,1,2,3,4,5,6,7,8,10,11,13,15}
C-B={0,1,2,3,4,5,7,8,10,11,13,15}
{0,1,2,3,4,5,7,8,10,11,13,15}uA={0,1,2,3,4,5,6,7,8,10,11,13,15}
(BnC)uA= {2,4,6,8,9,12,17}
BnC= {6,9,12}
{6,9,12}uA= {2,4,6,8,9,12,17}
Sper ca te-am ajutat :)