{

&print("Test 1: ");
define fact1 = fn(n) [ if (n equal? 1) then 1 else (n * &fact1( (n - 1))) ];
&println( &fact1(10) );

&print("Test 2: ");
letrec (fact2 = fn(n) [ if (n equal? 1) then 1 else (n * &fact2( (n - 1))) ]) in {
        &println( &fact2(10));
};

&print("Test 3: ");
letrec (odd?  = fn(n) [if (n equal? 0) then 0 else &even?( (n - 1))],
        even? = fn(n) [if (n equal? 0) then 1 else &odd?( (n - 1))]) in {
  &print("&odd?(5): ");
  &print(&odd?(5));
  &print(", &even?(11): ");
  &println(&even?(11));
};

}