add header

Author: arsalan0c

src/examples/liars.js

@@ -0,0 +1,32 @@
+/*
+  SICP JS Exercise 4.33
+
+  This file contains a solution to the Liar's puzzle
+*/
+
+function distinct(items) {
+     return is_null(items)
+         ? true
+         : is_null(tail(items))
+         ? true
+         : is_null(member(head(items), tail(items)))
+             ? distinct(tail(items))
+             : false;
+}
+
+const betty = amb(1, 2, 3, 4, 5);
+const ethel = amb(1, 2, 3, 4, 5);
+const joan = amb(1, 2, 3, 4, 5);
+const kitty = amb(1, 2, 3, 4, 5);
+const mary = amb(1, 2, 3, 4, 5);
+
+require(amb(kitty === 2, betty === 3));
+require(amb(ethel === 1, joan === 2));
+require(amb(joan === 3, ethel === 5));
+require(amb(kitty === 2, mary === 4));
+require(amb(mary === 4, betty === 1));
+
+require(distinct(list(betty, ethel, joan, kitty, mary)));
+
+list(list('betty', betty), list('ethel', ethel), list('joan', joan),
+  list('kitty', kitty), list('mary', mary));