For the string $(((($y$$q$))->)->(($x$)$xy$))$

$,$ choose ALL statements that apply.

Question $2$Answer

a$.$

This is a Boolean formula

b$.$

This is not a first$-$order formula because it contains a term that is not in an atomic formula

c$.$

The complexity is $6$

d$.$

This is a first$-$order formula with the following valid formula calculation:

$\backslash$phi xy$,$ y$,$ q$,($y $$ q$),(($y $$ q$)),((($y $$ q$))->),(($x$)\backslash$phi xy$),$

$(((($y $$ q$))->)->(($x$)\backslash$phi xy$))$