is a, is not a, isn't a, is all, is not all, isn't all

• operator to test whether a value is or isn't a particular type

• The following expressions all yield true: +

   pi is a number

   pi is not an integer

   "123, 12.5" is a point

   (snow is greater than rain) is a boolean

   6 is a digit

   "(),.;:!?[]{}%\'/" & quote is all punctuation

   tab is a controlChar

   "A" is an uppercase

   "ABCdef" is not all uppercase

   space is a blank

   space tab return is all blankOrReturn