anchor.diff:  ;; Common number functions
   (defmacro inc (x) `(+ ,x 1))
   (defmacro dec (x) `(- ,x 1))
  +
  +(defun max (& xs)
  +  (reduce (lambda (x y) (if (> y x) y x)) (car xs) xs))
  +
  +(defun min (& xs)
  +  (reduce (lambda (x y) (if (< y x) y x)) (car xs) xs))
   
   ;; Predicates
   (defun nil? (x)
  
positive.code: ;; Stdio macros
  (defmacro printf (fs & a) `(print (format ,fs ,@a)))
  (defmacro println (x) `(printf "%s\n" ,x))
  
negative.code: 
  ;; More normal flow control
  (defmacro if (p x y) `(cond (,p ,x) (t ,y)))
  (defmacro if-not (p x y) `(if (not ,p) ,x ,y))
  (defmacro when (p & b) `(if ,p (do ,@b) nil))
  (defmacro when-not (p & b) `(when (not ,p) ,@b))
  (def unless when-not)
  
  ;; Append
  (defun append (x y)
  