anchor.diff:      [(empty? vars) `((lambda () ,@body))]
       [else `((lambda ,(make-vars (caar vars))
                 (cond
  -                [,(make-test (caar vars)) (when-let* ,(cdr vars) ,@body)]
  +                [,(make-var (caar vars)) (when-let* ,(cdr vars) ,@body)]
                   [else nil]))
               ,(make-binding (cdar vars)))]))
   
  
positive.code:      (when (and ,@(cars vars)) ,@body))
      ,@(map make-let-binding vars)))
  
  (defmacro if-let (vars then else)
    "Evaluate THEN or ELSE, depending on the truthiness of all variables
     bound (as per [[let]]) in VARS."
    `((lambda ,(cars vars)
        (if (and ,@(cars vars))
          ,then
          ,else))
      ,@(map make-let-binding vars)))
  
  (defmacro when-let* (vars &body)
    "Bind each pair of `(name value)` of VARS, checking if the value is
     truthy before binding the next, and finally evaluating BODY. As with
  
negative.code: 
     When `bar` has an index `baz`, it will be bound to `foo` and
     printed. If not, the print statement will not be executed."
    `((lambda ,(make-vars (car var)) (when ,(make-var (car var)) ,@body)) ,(cadr var)))
  
  (defmacro if-let (vars then else)
    "Evaluate THEN or ELSE, depending on the truthiness of all variables
     bound (as per [[let]]) in VARS.
  
     ### Example
     ```cl
     > (if-let [(a 1)
     .          (b false)]
     .   b
     .   a)
     out = 1
     ```"
    `((lambda ,(cars vars)
        (if (and ,@(cars vars))
          ,then
          ,else))
      ,@(map make-let-binding vars)))
  
  (defmacro if-with (var then else)
    "Bind the pair VAR of the form `(name value)`, evaluating THEN if the
     value is truthy or ELSE if not.
  
     ### Example
     ```cl
     > (if-with ((a b c) (values-list false 1 2))
     .   a
     .   (+ b c))
     out = 3
     ```"
    `((lambda ,(make-vars (car var))
        (if ,(make-var (car var))
          ,then
          ,else))
       ,(cadr var)))
  
  (defun make-setting (var) :hidden
    (if (= (n var) 2)
  