Problem 2. These questions are about Predicate Logic. The first two questions are about the structure N = (INU{0}, fN) where fN(x,y) = x + y, gN(x,y) = x * y, EN(x,y) if x = y, and cN = 0 and dN = 1.
a) Express the following as a predicate-logic sentence in the vocabulary of N: for every number x, if x + x is equal to x * x then x = 0. Just give the sentence, no other justification needed.
b) Apply the recursive definition of truth-value to decide whether or not N satisfies the sentence xE(f(d, d), x). Show each step.
c) Apply the procedure learned in the course to put the following formula into Prenex Normal Form: (h'm)OhEF(h)dhE)mA. Show each step.
d) Give a recursive definition NQ(F) that returns the total number of quantifiers in the predicate-logic formula F. For instance, NQ(3xVy(F(x,y) A3xP(x))) = 3. Just give the recursive definition, no other justification is needed.