The free variables (F.V.) of (\x.x (\y.y z)) are
The free variables of (\x. y \y. x z) are
F.V.((\x . x y z) (\y. y x)) are
The expression (\x.\y. x y \z.z \t.t u) is equivalent to
The expression ((\x.\y. x y \z.z) \t.t u) is equivalent to
The expression ((\x. x y \y. x y) \y.y) is alpha equivalent to
The expression ((\x. \y. x y x) (\x. y) z) is alpha equivalent to