Logical Equivalence x can fool y Let F(x,y) mean x can fool y There is exactly one person who everybody can fool: ∃y(∀xF(x,y))^∀z(∀wF(w,z)) -> y=z How would I say exactly one person who nobody can fool?

Nobody can fool a: ∀x(-F(x,a)

There exists somebody nobody can fool:∃a(∀x-F(x,a))

She is unique: ∃a(∀x-F(x,a))^∀z(∀x-F(x,z)) -> z=a