lambda-calc.clj

(def first (fn [first] 
             (fn [second] first)))
(def second (fn [first] 
             (fn [second] second)))

(def make-pair (fn [first] (fn [second] (fn [func] ((func first) second)))))

(def TRUE first)
(def FALSE second)

(def COND (fn [exp1]
            (fn [exp2]
              (fn [c]
                ((c exp1) exp2)))))

(def NOT (fn [c] 
           (((COND FALSE) TRUE) c)))

(def AND (fn [exp1] 
          (fn [exp2] 
            (((COND exp2) FALSE) exp1))))

(def OR (fn [exp1]
          (fn [exp2]
            (((COND TRUE) exp2) exp1))))

(def zero identity)

(def succ (fn [n] 
            (fn [s] ((s FALSE) n))))

(def pred (fn [n] 
            (n second)))

(def iszero (fn [n] 
            (n first)))

(def pred (fn [n] 
            (((iszero n) n) (n second))))

(def one (succ zero))
(def two (succ one))
(def three (succ two))

(def two (pred three))