values
 s = [3,8,5,2,9,3,4,5,6,7,1];

functions

  filter[@a] : (@a -> bool) * seq of @a -> seq of @a
  filter(p,l) == cases l:
                  [] -> [],
                  [h]^t -> if p(h) then [h]^filter[@a](p,t) else filter[@a](p,t)
                 end;

   lessSix: int -> bool
   lessSix(x) == (x < 6);

   prefixA: seq of char -> bool
   prefixA(x) == (hd x = 'a');


   fmap[@a,@b] : (@a -> @b) * seq of @a -> seq of @b
   fmap(f,l) == cases l:
                  [] -> [],
                  [h]^t -> [f(h)]^fmap[@a,@b](f,t) 
                 end;


   dups: int -> int
   dups(x) ==  x * x;


values
-- Lambda-expressions

Inc = lambda n:int & n+1;
Mul = lambda n:nat & lambda m:nat & n+m;