Incorrect Answer.

The "formula" x ( y F(x, y) y M(x, M(y))) is not a meaningful formula in predicate logic. The "subformula" M(y) serves as an argument to the predicate M in M(x, M(y)). This is not allowed as arguments to predicates have to be terms. Inspect the definition of predicate logic formulas in Chapter 2 for details.
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