EX-OR, A ⊕ B = ${A}'B + A{B}'$
Dual of EX-OR = $({A}'+B).(A+{B}')$ = ${A}'{B}'+AB$ = A⊙B = EX-NOR
[Note :
Dual is different concept from Complement
In Dual, Replace AND with OR , OR with AND and replace 1's by 0's and 0's by 1's
In complement, In addition to above, we also replace Binary variables by its complement's, mean x by x' or x' by x.
In case of EX-OR , dual of EX-OR is same as its complement, but for different expression, it may differ. ]