examples/peano.spl

   1 ackerman(m, n){
   2         if(m ==0){
   3                 return n+1;
   4         } else {
   5                 if(m>0 && n == 0){
   6                         return ackerman(m-1, 1);
   7                 } else {
   8                         return ackerman(m-1, ackerman(m, n-1));
   9                 }
  10         }
  11 }
  12
  13 hyper(n, a, b){
  14         if(n == 0){                                     return b + 1;
  15         } else { if(b == 0 && n == 1){  return a;
  16         } else { if(b == 0 && n == 2){  return 0;
  17         } else { if(b == 0 && n >= 3){  return 1;
  18         } else {                                                return hyper(n-1, a, hyper(n, a, b - 1));
  19         }}}}
  20 }
  21
  22 main(){
  23         print("s(3)=", hyper(0, 3, 3));
  24         print("3+3=", hyper(1, 3, 3));
  25         print("3*3=", hyper(2, 3, 3));
  26         print("3^4=", hyper(3, 3, 4));
  27         print("2|3=", hyper(4, 2, 3));
  28
  29         print("a(0, 0)=", ackerman(0, 0));
  30         print("a(0, 1)=", ackerman(0, 1));
  31         print("a(0, 2)=", ackerman(0, 2));
  32         print("a(0, 3)=", ackerman(0, 3));
  33
  34         print("a(1, 0)=", ackerman(1, 0));
  35         print("a(1, 1)=", ackerman(1, 1));
  36         print("a(1, 2)=", ackerman(1, 2));
  37         print("a(1, 3)=", ackerman(1, 3));
  38
  39         print("a(2, 0)=", ackerman(2, 0));
  40         print("a(2, 1)=", ackerman(2, 1));
  41         print("a(2, 2)=", ackerman(2, 2));
  42         print("a(2, 3)=", ackerman(2, 3));
  43
  44         print("a(3, 0)=", ackerman(3, 0));
  45         print("a(3, 1)=", ackerman(3, 1));
  46         print("a(3, 2)=", ackerman(3, 2));
  47         print("a(3, 3)=", ackerman(3, 3));
  48
  49         print("a(4, 0)=", ackerman(4, 0));
  50 /*      print("a(4, 1)=", ackerman(4, 1));
  51         print("a(4, 2)=", ackerman(4, 2));
  52         print("a(4, 3)=", ackerman(4, 3));*/
  53 }