primes2.lam

-- outputs characteristic sequence of primes
\io let
   zero  = \x\y.x;
   one   = \x\y.y;
   consz = \xs\p.p zero xs;
   oneS  = \cont\x\xs\p.p x (xs cont);
   zeroS = \cont\x\xs.consz (xs cont);
   fix   = \f.(let x=f x in x);
   ones  = fix (\ones\p.p one ones);
   sieve = fix(\sv\n\x\xs\p.p x (x xs (xs (fix n)) (sv (\r.oneS (n r)))));
   main  = consz (consz ones (sieve zeroS))
in main

-- test with ./blc run primes2.lam