(let pad (comp str (pad-right " " 10)))

(print "a         b         | (and a b) (or a b)  (not a)   (xor a b)")
(print (str* "-" 20) "+" (str* "-" 40))

(join "\n"
  (for a  [false :a]
       b  [false :b]
    (... str (pad a) (pad b) "| "
      (for op [and or not xor]
        (pad (if (= op not) (op a) (op a b)))))))