add examples

examples/constDivZero.hs

@@ -0,0 +1,3 @@
+k x y = x;
+main = k 3 ((/#) 1 0);
+

examples/factorial.hs

@@ -0,0 +1,7 @@
+fac n = case (==#) n 0 of
+    { 1 -> 1
+    ; 0 -> (*#) n (fac ((-#) n 1))
+    };
+
+main = fac 3;
+

examples/sumList.hs

@@ -0,0 +1,9 @@
+nil = Pack{0 0};
+cons x y = Pack{1 2} x y;
+list = cons 1 (cons 2 (cons 3 nil));
+sum l = case l of
+    { 0      -> 0
+    ; 1 x xs -> (+#) x (sum xs)
+    };
+main = sum list;
+