anchor.diff:  ;;;; several higher order functions
  +
  +(in-package "CLAMP")
   
   (def testify (x)
     "If passed a function, returns it. Otherwise returns a function which
      tests equality for the object passed"
     (if (functionp x) x [iso x _]))
   
  -(def del (test xs &rest args)
  +(def rem (test xs &rest args)
     "Version of remove that uses testify"
     (apply #'remove-if (testify test) xs args))
   
  
positive.code: 
  (def mappend (f &rest xss)
    "Joins the results of mapping f over xs"
    (apply #'join (apply #'mapf f xss)))
  
  (def alter (old new seq)
    "Substitues everything passes the testified version of old
     with new (which can be a function)"
    (with (test (testify old) next (if (functionp new)
  
negative.code:   "Version of mem that uses testify"
    (apply #'member-if (testify test) xs args))
  
  (def find (test xs &rest args)
    "Version of find that uses testify"
    (apply #'find-if (testify test) xs args))
  
  (def count (test xs &rest args)
    "Version of count that uses testify"
    (apply #'count-if (testify test) xs args))
  
  