What does this symbol represent?

What does this symbol represent?

Write the symbol for S complement.

If Set A = {2, 4, 6, 8, 10, 12}, set B = {3, 6, 9, 12, 15} and set C = {1, 4, 7, 10, 13, 16}. Find;

(i) A ∪ B

(ii) A ∩ B

(iii) B ∩ A

(iv) B ∪ A

(v) B ∪ C

(vi) Is A ∪ B = B ∪ A?

(vii) Is B ∩ C = B ∪ C?

If A = {1, 3, 7, 9, 10}, B = {2, 5, 7, 8, 9, 10}, C = {0, 1, 3, 10}, D = {2, 4, 6, 8, 10}, E = {negative natural numbers} and F = {0}

Find:

(i) A ∪ B

(ii) E ∪ D

(iii) C ∪ F

(iv) C ∪ D

(v) B ∪ F

(vi) A ∩ B

(vii) C ∩ D

(viii) E ∩ D

(ix) C ∩ F

(x) B ∩ F

(xi) (A ∪ B) ∪ (A ∩ B)

(xii) (A ∪ B) ∩ (A ∩ B)

If A={a,b,c,d,e,f,g} and B={a,n,f,j,g,h}. List the members of

i. B'

ii. A'