$2.$ For the following wffs$,$ indicate which variables are free and which are bound $($you can use $\text{'}$F$\text{'}$ for free and $\text{'}$B$\text{'}$ for bound.$)$ Either $($i$)$ draw a vertical line underneath each variable with the letters $\text{'}$F$\text{'}$ or $\text{'}$B$\text{'}$ at the bottom of each vertical line or $($ii$)$ color bound variables red and free variables green. Make sure you know which symbols are used for variables. Not every symbol in the language of predicate logic is used for variables. The reading $($Scope$,$ binding, and quantifier expansions$)$ lists the symbols that are used for variables and the symbols that used for the names of objects $($i$.$e$.,$ individual constants$).$ Names of objects are not names of variables. The free$/$bound distinction only applies to variables. It does not apply to individual constants $($i$.$e$.,$ names of objects$)$

$($a$)($x$)($y$)($Ez$)(($Ayazwbd $$ Bzfhy$)$ v $($Fxzc $$ Hzzuju$))$

$($b$)($Ex$)($Ey$)($Hyabwa $($z$)($Fzvhky v Hxyyx$))$

$($c$)($z$)($Ex$)($y$)$ Axyzyyw $($y$)$ Bxyxzavz