QUESTION $3$

$7$

Let

$P$ and $Q$ be two predicate symbols, each with two arguments,

$f$ a function symbol with one argument and

c a constant symbol.

$x,y,z$ are variables

For each of the following, state whether it is a term or a well$-$formed formula $($wff$)$ or neither. If it is neither a term nor a wff$,$ state the reason.

Question $3\mathrm{.}1P(x,Q(x,y))$

Question $3\mathrm{.}2$EExEEcP$(x,c)$

Question $3\mathrm{.}3$EEy$(Q(x,y{)}^{{?}^{?}}(f(x)vvf(y)))$

Question $3\mathrm{.}4P(x,c)vvEExQ(x)$

Question $3\mathrm{.}5$ AAxP$(x,f(c))$EEyQ$(x,y)$

Question $3\mathrm{.}6Q(x,f(x))P(f(x),y)$

Question $3\mathrm{.}7,f(f(f(y)))$