(defprolog woman
   martha <--;
    joan <--;)
    
(prolog? (woman martha))

(prolog? (woman jean))

(prolog? (woman X)) 

(prolog? (woman X) (return X))

(prolog? (findall X (woman X) Y) (return Y))

(prolog? (is X (+ 1 1)) (return X))  
    
(defprolog f
          (- a) <--;)

(prolog? (f X))

(prolog? (f a))

(defprolog lived
   "Adam" 930 <--;
   "Seth" 912 <--;
   "Enos" 905 <--;
   "Ca-i'nan" 910 <--;
   "Mahal'aleel" 895 <--;
   "Jared" 962 <--;
   "Enoch" 365 <--;
   "Methu'selah" 969 <--;
   "Lamech" 777 <--;)

(defprolog begat
   "Adam" "Seth"  <--;
   "Seth" "Enos" <--;
   "Enos" "Ca-i'nan" <--;
   "Ca-i'nan" "Mahal'aleel" <--;
   "Mahal'aleel" "Jared" <--;
   "Jared" "Enoch" <--;
   "Enoch" "Methu'selah" <--;
   "Methu'selah" "Lamech" <--;)

(prolog? (findall Age (lived Person Age) Ages) 
         (return (sum Ages)))
         
(defprolog total
           [] 0 <--;
           [X | Y] N <-- (total Y M) (is N (+ M X));)

(prolog? (findall Age (lived Person Age) Ages) 
         (total Ages Total) 
         (return Total))
         
(prolog? (when (> 6 7)))

(prolog? (when (> 16 7)))         
         
(define foo
       X -> (prolog? (is Y (* (receive X)  (receive X))) (return Y)))

(foo 9)
        
(defprolog woman
    X <-- !  (married-to X john);
   martha <--;)

(defprolog married-to
   joan john <--;) 
   
(prolog? (woman joan))  

(prolog? (woman martha))         

(defprolog neg
  P <-- (call P) ! (when false);
  _ <--;)

(prolog? (neg (woman susan)))

(prolog? (neg (woman joan)))

(defprolog f
   X <-- (g1 X) (h X);
   X <-- (g1 X) (i X);
   X <-- (g1 X) (j X);)
   
(defprolog g1
  a <--;)
  
(defprolog h
   a <--;)
   
(defprolog i
   a <--;
   b <--;)
   
(defprolog j
   b <--;)    
   
(prolog? (g1 a))        

(defprolog f
   X <-- (g1 X) (fork (h X) (i X) (j X));)
   
(prolog? (f a))