theory Intro

imports Base

begin

chapter {* Introduction *}

text {*

  If your next project requires you to program on the ML-level of Isabelle,

  then this tutorial is for you. It will guide you through the first steps of

  Isabelle programming, and also explain tricks of the trade. The best way to

  get to know the ML-level of Isabelle is by experimenting with the many code

  examples included in the tutorial. The code is as far as possible checked

  against recent versions of Isabelle.  If something does not work, then

  please let us know. If you have comments, criticism or like to add to the

  tutorial, feel free---you are most welcome!

*}

section {* Intended Audience and Prior Knowledge *}

text {* 

  This tutorial targets readers who already know how to use Isabelle for

  writing theories and proofs. We also assume that readers are familiar with

  the functional programming language ML, the language in which most of

  Isabelle is implemented. If you are unfamiliar with either of these two

  subjects, you should first work through the Isabelle/HOL tutorial

  \cite{isa-tutorial} or Paulson's book on ML \cite{paulson-ml2}.

*}

section {* Existing Documentation *}

text {*

  The following documentation about Isabelle programming already exists (and is

  part of the distribution of Isabelle):

  \begin{description}

  \item[The Implementation Manual] describes Isabelle

  from a high-level perspective, documenting both the underlying

  concepts and some of the interfaces. 

  \item[The Isabelle Reference Manual] is an older document that used

  to be the main reference of Isabelle at a time when all proof scripts 

  were written on the ML-level. Many parts of this manual are outdated 

  now, but some  parts, particularly the chapters on tactics, are still 

  useful.

  \item[The Isar Reference Manual] is also an older document that provides

  material about Isar and its implementation. Some material in it

  is still useful.

  \end{description}

  Then of course there is:

  \begin{description}

  \item[The code] is of course the ultimate reference for how

  things really work. Therefore you should not hesitate to look at the

  way things are actually implemented. More importantly, it is often

  good to look at code that does similar things as you want to do and

  to learn from other people's code.

  \end{description}

*}

section {* Typographic Conventions *}

text {*

  All ML-code in this tutorial is typeset in highlighted boxes, like the following 

  ML-expression:

  \begin{isabelle}

  \begin{graybox}

  \isacommand{ML}~@{text "\<verbopen>"}\isanewline

  \hspace{5mm}@{ML "3 + 4"}\isanewline

  @{text "\<verbclose>"}

  \end{graybox}

  \end{isabelle}

  These boxes corresponds to how code can be processed inside the interactive

  environment of Isabelle. It is therefore easy to experiment with what is 

  displayed. However, for better readability we will drop the enclosing 

  \isacommand{ML}~@{text "\<verbopen> \<dots> \<verbclose>"} and just write:

  @{ML [display,gray] "3 + 4"}

  Whenever appropriate we also show the response the code 

  generates when evaluated. This response is prefixed with a 

  @{ML_response [display,gray] "3 + 4" "7"}

  The usual user-level commands of Isabelle are written in bold, for 

  example \isacommand{lemma}, \isacommand{foobar} and so on.  

  We use @{text "$"} to indicate that a command  needs to be run 

  in a Unix-shell, for example:

  @{text [display] "$ ls -la"}

  Pointers to further information and Isabelle files are typeset in 

  italic and highlighted as follows:

  \begin{readmore}

  Further information or pointers to files.

  \end{readmore}

*}

end