Those of you who already have some experience of programming, or experience of simply using a computer, will know that computers can be very unforgiving. They are fussy, and unless you get things exactly right they will complain. The program described in this document has grown out of an attempt to help you to understand what is going on when the computer complains. It is designed to help you with the Miranda scripts that you will be writing as part of the process of learning Miranda (or indeed any other similar functional programming language like Gofer or Haskell).