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:         else op (elemAt list n) (fold' (n + 1));
      in fold' 0;
  
    /* Left fold: `fold op nul [x_1 x_2 ... x_n] == op (... (op (op nul
       x_1) x_2) ... x_n)'.
  
       Example:
         lconcat = foldl (a: b: a + b) "z"
         lconcat [ "a" "b" "c" ]
         => "zabc"
    */
    foldl = op: nul: list:
      let
  
negative.code:        all (x: x < 3) [ 1 2 3 ]
         => false
    */
    all = builtins.all or (pred: foldr (x: y: if pred x then y else false) true);
  
    /* Count how many times function `pred' returns true for the elements
       of `list'.
  