To decompile the "formula" x (F(x) M(M(x))),
we break it into significant "subformulas".
The "subformula" M(x) serves as an argument to the predicate M in M(M(x)).
This is not allowed
as arguments to predicates have to be terms. Inspect the
definition of predicate logic formulas in Chapter 2 for details.
Thus, x (F(x) M(M(x))) is not
a formula of predicate logic!
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