diff -r e66bd5c563eb -r b5b5583a3a08 progs/defs.fun
--- a/progs/defs.fun	Mon Jul 27 11:02:48 2020 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,85 +0,0 @@
-
-def zero(x) = 0;
-
-def suc(x) = x + 1;
-
-def pred(x) =
-  if x == 0 then x else x - 1;
-
-def add(x, y) =
-  if x == 0 then y else suc(add(x - 1, y));
-
-def mult(x, y) =
-  if x == 0 then 0 else add(y, mult(x - 1, y));
-
-def pow(x, y) =
-  if y == 0 then 1 else mult(x, pow(x, y - 1));
-
-def fib(n) = if n == 0 then 0 
-             else if n == 1 then 1 
-             else fib(n - 1) + fib(n - 2);
-
-def fact(n) =
-  if n == 0 then 1 else n * fact(n - 1);
-
-def ack(m, n) = if m == 0 then n + 1
-                else if n == 0 then ack(m - 1, 1)
-                else ack(m - 1, ack(m, n - 1));
-
-def stack_test(x) = x + 1 + 2 + 3 + 4 + 5;
-
-def div(x, y) = x / y;   //integer division
-
-def rem(x, y) = x % y;   //remainder
-
-def gcd(a, b) =
-  if b == 0 then a else gcd(b, a % b);
-
-def is_prime_aux(n, i) = 
-  if n % i == 0 then 0
-  else if (i * i) <= n then is_prime_aux(n, i + 1)  
-  else 1;
-
-def is_prime(n) = if n == 2 then 1 else is_prime_aux(n, 2);
-
-def primes(n) = 
-  if n == 0 then 0
-  else if is_prime(n) == 1 then (write n; primes(n - 1)) 
-  else primes(n - 1);
-
-def is_collatz(n) =
-  if n == 1 then 1
-  else if n % 2 == 0 then is_collatz(n / 2)
-  else is_collatz(3 * n + 1);  
-
-def collatz_aux(n, i) = 
-  if i > n then 0
-  else if is_collatz(i) == 1 then (write i; collatz_aux(n, i + 1)) 
-  else collatz_aux(n, i + 1);
-
-def collatz(n) = collatz_aux(n, 1);
-
-def facT(n, acc) =
-  if n == 0 then acc else facT(n - 1, n * acc);
-
-
-//zero(3)
-//suc(8)
-//pred(7)
-//write(add(3, 4))
-//mult(4,5)
-//pow(2, 3)
-//fib(20)
-//(write(fact(5)) ; fact(6))
-//(write(1) ; 2)
-//write(ack(3, 12))   // for tail-rec test
-//stack_test(0)
-//(write (div(11, 3)); rem(11, 3))
-//gcd(54, 24)
-//is_prime(2)
-primes(1000)
-//primes(1000000)
-//collatz(4000)
-//collatz(5000)
-//facT(6, 1)
-