Formulate the requirements below as sentences of first order logic and show 
that the two of them cannot be true together in any interpretation. (This is 
the barber's paradox by Bertrand Russell.)

(1) Anyone who does not shave himself must be shaved by the barber [note the 
barber - some unique person, not a barber]

(2) Whomever the barber shaves, must not shave himself.

Hints: introduce a constant for the barber and a binary predicate Shaves(x,y).