Incorrect Answer.
Given the predicate logic model
A = {a,b,c,d};
PM = {a,b}
QM = {(a,b), (b,b), (c,b)}
fM (a) = b, fM (b) = b, fM (c) = a, and fM (d) = c
the formula
x Q(f(x),x)
is satisfied in this model if, and only if, for all values of x the pair
(fM(x),x) is in QM. To answer this, we simply compute
all these pairs.
- If the value of x is a, then the resulting pair is (fM(a),a),
which is (b,a). Since this pair is not in QM, we already see that
the formula is not satisfied in this model. Thus, there is no need to
generate the remaining pairs.
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