Cameron Moy camoy

A logic puzzle called "Prize Box" from the ASCM problem solving competition:

Three boxes, 3 signs: Only one box has the prize; n is odd if and only if two signs are true. Sign A says "n is even and box 1 has the prize." Sign B says "n + 4 is a multiple of 3 or box 3 has the prize." Sign C says "n is odd or box 2 has the prize." Given that n is a single digit positive integer where every digit is equally likely, which

Keybase proof

I hereby claim:

I am camoy on github.
I am camoy (https://keybase.io/camoy) on keybase.
I have a public key whose fingerprint is CC10 FC49 A531 78CF 4DAA 0CAF 1CE9 059A 203F CAE1

To claim this, I am signing this object:

	(* Exercise: Write the class definition (no methods) for a linked list in
	Java. *)

	(* Bad Approach:

	class List<T> {
	T data;
	List<T> next;
	}

	(* This is an OCaml adaptation of (Y Y) Works! by Felleisen
	and Friedman. An updated version of the same essay is
	available in the Little Schemer, Chapter 9. To run the
	examples you have to enable the -rectypes flag. *)

	(* Let's define the length function. *)

	let rec length xs =
	match xs with
	\| [] -> 0

	import qualified Data.Set.Monad as S

	fix f init = until (\x -> x == f x) f init
	close rstar = fix (\s -> s `S.union` (rstar s))
	rstar g s = do { x <- s; (x, y) <- g; pure y }
	reachable g = close (rstar g)

	-- g1 = S.fromList [(1, 2), (2, 3), (3, 1), (4, 1)]
	-- reachable g1 (S.singleton 1) == S.fromList [1, 2, 3]