palindrome.clj

(defn palindrome-o [x]
  (exist [a b c d]
    (digit-o a) (digit-o b) (digit-o c) (digit-o d)
    (nonrel/project [a b c d]
     (== x (* (+ (* 10 a) b)
              (+ (* 10 c) d)))
     (nonrel/project [x]
      (== (> x 0) true)
      (== (>= x 100) true)
      (== (mod (int (/ x 1000)) 10)
          (mod (int (/ x 1)) 10))
      (== (mod (int (/ x 100)) 10)
          (mod (int (/ x 10)) 10))))))

(defn palindrome []
  (let [r (range 9)]
    (for [a r b r
          c r d r
          :let  [x (* (+ (* 10 a) b)
                      (+ (* 10 c) d))]
          :when (and (> x 0)
                     (>= x 100)
                     (= (mod (int (/ x 1000)) 10)
                        (mod (int (/ x 1)) 10))
                     (= (mod (int (/ x 100)) 10)
                        (mod (int (/ x 10)) 10)))]
      x)))