∀p∈{people}( ∃t∈{time}( Person 'p' can be fooled at time 't' ) ) ∃p∈{people}( ∀t∈{time}( Person 'p' can be fooled at time 't' ) ) ¬( ∀p∈{people}( ∀t∈{time}( Person 'p' can be fooled at time 't' ) ) ) -- Abe Lincoln