Assignment:
A set A subset or equal to R is called an F_&(F sigma) set if it can be written as the countable union of closed sets. A set B subset or equal to R is called G_&(G sigma) if it can be written asthe countable intersection of open sets.
1-Argue that a set A is a G_& (G sigma) set if and only if its complement is an F_& (F sigma)set.
Provide complete and step by step solution for the question and show calculations and use formulas.