anchor.diff:  (in-package :serapeum)
   (in-readtable :fare-quasiquote)
  -
  -(import 'uiop:nest)
   
   (export '(eval-and-compile
             no nor nand
  
positive.code:               (lambda (needle hole)
                  (append1 hole needle))))
  
  (defmacro select (keyform &body clauses)
    "Like `case', but with evaluated keys.
  
  
negative.code:           ensure ensure2
            ~> ~>>
            cond-every
            nest))
  
  (defmacro prog0 (&body body)
    "Execute BODY like `progn' but return nothing."
  