anchor.diff:     (=>? (prefixp '(1 2 3) '())            NIL)
      (=>? (prefixp '(0 1 2 3 4) '(1 2 3))   NIL)
      (=>? (prefixp '(0 1 2 3 4) '(2 3 4))   NIL)
  -   (=>? (prefixp '(0 1 2 3) '(0 1 2 3 4)) T))
  +   (=>? (prefixp '(0 1 2 3) '(0 1 2 3 4)) T)
  +   (=>? (prefixp '(3 4 5) '(3 4))         NIL))
     )
  +
  
positive.code:    (prefixp '(0 1 2 3 4) '(1 2 3))   => NIL
     (prefixp '(0 1 2 3 4) '(2 3 4))   => NIL
     (prefixp '(0 1 2 3) '(0 1 2 3 4)) => T
  "
    :hint
    nil
  
negative.code: ;;;; Last modified: 2013-10-15 22:24:04 tkych
  
  (define-practice
    :id       032
  