anchor.diff:         any isString [ 1 { } ]
          => false
     */
  -  any = builtins.any or (pred: fold (x: y: if pred x then true else y) false);
  +  any = builtins.any or (pred: foldr (x: y: if pred x then true else y) false);
   
     /* Return true iff function `pred' returns true for all elements of
        `list'.
  
positive.code:        => { right = [ 5 3 4 ]; wrong = [ 1 2 ]; }
    */
    partition = builtins.partition or (pred:
      fold (h: t:
        if pred h
        then { right = [h] ++ t.right; wrong = t.wrong; }
        else { right = t.right; wrong = [h] ++ t.wrong; }
  
negative.code:         else op (foldl' (n - 1)) (elemAt list n);
      in foldl' (length list - 1);
  
    /* Strict version of `foldl'.
  
       The difference is that evaluation is forced upon access. Usually used
       with small whole results (in contract with lazily-generated list or large
  