Please use first-order logic to answer the question. We cannot explicitly define function and relation.

Question 6 (8 marks). Let v to be a valuation of first order logic with equality. Let D be the domain of v. (a) Give a set of formulas, Ea, such that (a)' = 1 if and only if D contains exactly 3 elements. Briefly explain why your choice of Sa is correct. (b) Give a set of formulas, Eb, such that (Eb)' = 1 if and only if D contains an infinite number of elements. Briefly explain why your choice of Eb is correct. Question 6 (8 marks). Let v to be a valuation of first order logic with equality. Let D be the domain of v. (a) Give a set of formulas, Ea, such that (a)' = 1 if and only if D contains exactly 3 elements. Briefly explain why your choice of Sa is correct. (b) Give a set of formulas, Eb, such that (Eb)' = 1 if and only if D contains an infinite number of elements. Briefly explain why your choice of Eb is correct