: bitwise ( ab- )
  cr
  over     "a = %d\n" puts
  dup      "b = %d\n" puts
  2over and "a and b = %d\n" puts
  2over or  "a or b = %d\n" puts
  2over xor "a xor b = %d\n" puts
  over not "not a = %d\n" puts
  2over <<  "a << b = %d\n" puts
  2over >>  "a >> b = %d\n" puts
  2drop ;
