doc-src/LaTeXsugar/Sugar/Sugar.thy
author webertj
Mon Nov 27 17:13:10 2006 +0100 (2006-11-27 ago)
changeset 21558 63278052bb72
parent 18708 4b3dadb4fe33
child 22329 e4325ce4e0c4
permissions -rw-r--r--
typo fixed
nipkow@15337
     1
(*<*)
nipkow@15337
     2
theory Sugar
kleing@15366
     3
imports LaTeXsugar OptionalSugar
nipkow@15337
     4
begin
nipkow@15337
     5
(*>*)
nipkow@15337
     6
nipkow@15337
     7
section "Introduction"
nipkow@15337
     8
kleing@15385
     9
text{* This document is for those Isabelle users who have mastered
nipkow@15337
    10
the art of mixing \LaTeX\ text and Isabelle theories and never want to
nipkow@15337
    11
typeset a theorem by hand anymore because they have experienced the
nipkow@15337
    12
bliss of writing \verb!@!\verb!{thm[display]setsum_cartesian_product[no_vars]}!
nipkow@15337
    13
and seeing Isabelle typeset it for them:
nipkow@15337
    14
@{thm[display,eta_contract=false] setsum_cartesian_product[no_vars]}
nipkow@15342
    15
No typos, no omissions, no sweat.
nipkow@15342
    16
If you have not experienced that joy, read Chapter 4, \emph{Presenting
nipkow@15342
    17
Theories}, \cite{LNCS2283} first.
nipkow@15337
    18
nipkow@15337
    19
If you have mastered the art of Isabelle's \emph{antiquotations},
nipkow@15337
    20
i.e.\ things like the above \verb!@!\verb!{thm...}!, beware: in your vanity
nipkow@15337
    21
you may be tempted to think that all readers of the stunning ps or pdf
nipkow@15337
    22
documents you can now produce at the drop of a hat will be struck with
nipkow@15337
    23
awe at the beauty unfolding in front of their eyes. Until one day you
nipkow@15337
    24
come across that very critical of readers known as the ``common referee''.
nipkow@15337
    25
He has the nasty habit of refusing to understand unfamiliar notation
nipkow@15337
    26
like Isabelle's infamous @{text"\<lbrakk> \<rbrakk> \<Longrightarrow>"} no matter how many times you
nipkow@15337
    27
explain it in your paper. Even worse, he thinks that using @{text"\<lbrakk>
nipkow@15337
    28
\<rbrakk>"} for anything other than denotational semantics is a cardinal sin
nipkow@15342
    29
that must be punished by instant rejection.
nipkow@15337
    30
nipkow@15337
    31
nipkow@15337
    32
This document shows you how to make Isabelle and \LaTeX\ cooperate to
nipkow@15337
    33
produce ordinary looking mathematics that hides the fact that it was
nipkow@15471
    34
typeset by a machine. You merely need to load the right files:
nipkow@15471
    35
\begin{itemize}
nipkow@15471
    36
\item Import theory \texttt{LaTeXsugar} in the header of your own
nipkow@15471
    37
theory.  You may also want bits of \texttt{OptionalSugar}, which you can
nipkow@15471
    38
copy selectively into your own theory or import as a whole.  Both
nipkow@15471
    39
theories live in \texttt{HOL/Library} and are found automatically.
kleing@15378
    40
nipkow@15471
    41
\item Should you need additional \LaTeX\ packages (the text will tell
nipkow@15471
    42
you so), you include them at the beginning of your \LaTeX\ document,
nipkow@16153
    43
typically in \texttt{root.tex}. For a start, you should
nipkow@16153
    44
\verb!\usepackage{amssymb}! --- otherwise typesetting
nipkow@16153
    45
@{prop[source]"\<not>(\<exists>x. P x)"} will fail because the AMS symbol
nipkow@16153
    46
@{text"\<nexists>"} is missing.
nipkow@15471
    47
\end{itemize}
nipkow@15342
    48
*}
nipkow@15342
    49
nipkow@15342
    50
section{* HOL syntax*}
nipkow@15342
    51
nipkow@15342
    52
subsection{* Logic *}
nipkow@15342
    53
nipkow@16153
    54
text{* 
nipkow@16153
    55
  The formula @{prop[source]"\<not>(\<exists>x. P x)"} is typeset as @{prop"~(EX x. P x)"}.
nipkow@16153
    56
nipkow@16153
    57
The predefined constructs @{text"if"}, @{text"let"} and
nipkow@15342
    58
@{text"case"} are set in sans serif font to distinguish them from
nipkow@15342
    59
other functions. This improves readability:
nipkow@15342
    60
\begin{itemize}
nipkow@15342
    61
\item @{term"if b then e\<^isub>1 else e\<^isub>2"} instead of @{text"if b then e\<^isub>1 else e\<^isub>2"}.
nipkow@15342
    62
\item @{term"let x = e\<^isub>1 in e\<^isub>2"} instead of @{text"let x = e\<^isub>1 in e\<^isub>2"}.
nipkow@15342
    63
\item @{term"case x of True \<Rightarrow> e\<^isub>1 | False \<Rightarrow> e\<^isub>2"} instead of\\
nipkow@15342
    64
      @{text"case x of True \<Rightarrow> e\<^isub>1 | False \<Rightarrow> e\<^isub>2"}.
nipkow@15342
    65
\end{itemize}
nipkow@15342
    66
*}
nipkow@15342
    67
nipkow@15342
    68
subsection{* Sets *}
nipkow@15337
    69
nipkow@15342
    70
text{* Although set syntax in HOL is already close to
nipkow@15342
    71
standard, we provide a few further improvements:
nipkow@15342
    72
\begin{itemize}
nipkow@15342
    73
\item @{term"{x. P}"} instead of @{text"{x. P}"}.
nipkow@15342
    74
\item @{term"{}"} instead of @{text"{}"}.
nipkow@15342
    75
\item @{term"insert a (insert b (insert c M))"} instead of @{text"insert a (insert b (insert c M))"}.
nipkow@15342
    76
\end{itemize}
nipkow@15342
    77
*}
nipkow@15342
    78
nipkow@15342
    79
subsection{* Lists *}
nipkow@15342
    80
nipkow@15342
    81
text{* If lists are used heavily, the following notations increase readability:
nipkow@15342
    82
\begin{itemize}
nipkow@15342
    83
\item @{term"x # xs"} instead of @{text"x # xs"}.
nipkow@15342
    84
      Exceptionally, @{term"x # xs"} is also input syntax.
nipkow@15342
    85
If you prefer more space around the $\cdot$ you have to redefine
nipkow@15342
    86
\verb!\isasymcdot! in \LaTeX:
nipkow@15342
    87
\verb!\renewcommand{\isasymcdot}{\isamath{\,\cdot\,}}!
nipkow@15342
    88
nipkow@15342
    89
\item @{term"length xs"} instead of @{text"length xs"}.
kleing@15385
    90
\item @{term"nth xs n"} instead of @{text"nth xs n"},
nipkow@15342
    91
      the $n$th element of @{text xs}.
nipkow@15342
    92
kleing@15366
    93
\item The @{text"@"} operation associates implicitly to the right,
kleing@15366
    94
which leads to unpleasant line breaks if the term is too long for one
kleing@15366
    95
line. To avoid this, \texttt{OptionalSugar} contains syntax to group
kleing@15366
    96
@{text"@"}-terms to the left before printing, which leads to better
kleing@15366
    97
line breaking behaviour:
wenzelm@15673
    98
@{term[display]"term\<^isub>0 @ term\<^isub>1 @ term\<^isub>2 @ term\<^isub>3 @ term\<^isub>4 @ term\<^isub>5 @ term\<^isub>6 @ term\<^isub>7 @ term\<^isub>8 @ term\<^isub>9 @ term\<^isub>1\<^isub>0"}
kleing@15366
    99
nipkow@15342
   100
\end{itemize}
nipkow@15337
   101
*}
nipkow@15337
   102
nipkow@15337
   103
section "Printing theorems"
nipkow@15337
   104
nipkow@15689
   105
subsection "Question marks"
nipkow@15689
   106
nipkow@15689
   107
text{* If you print anything, especially theorems, containing
nipkow@15689
   108
schematic variables they are prefixed with a question mark:
nipkow@15689
   109
\verb!@!\verb!{thm conjI}! results in @{thm conjI}. Most of the time
nipkow@15689
   110
you would rather not see the question marks. There is an attribute
nipkow@15689
   111
\verb!no_vars! that you can attach to the theorem that turns its
nipkow@15689
   112
schematic into ordinary free variables: \verb!@!\verb!{thm conjI[no_vars]}!
nipkow@15689
   113
results in @{thm conjI[no_vars]}.
nipkow@15689
   114
nipkow@15689
   115
This \verb!no_vars! business can become a bit tedious.
nipkow@15689
   116
If you would rather never see question marks, simply put
nipkow@15689
   117
\begin{verbatim}
wenzelm@15983
   118
reset show_question_marks;
nipkow@15689
   119
\end{verbatim}
nipkow@15689
   120
at the beginning of your file \texttt{ROOT.ML}.
nipkow@15689
   121
The rest of this document is produced with this flag reset.
nipkow@16075
   122
nipkow@16075
   123
Hint: Resetting \verb!show_question_marks! only supresses question
nipkow@16075
   124
marks; variables that end in digits, e.g. @{text"x1"}, are still
nipkow@16075
   125
printed with a trailing @{text".0"}, e.g. @{text"x1.0"}, their
nipkow@16075
   126
internal index. This can be avoided by turning the last digit into a
nipkow@16075
   127
subscript: write \verb!x\<^isub>1! and obtain the much nicer @{text"x\<^isub>1"}. *}
nipkow@15689
   128
wenzelm@15983
   129
(*<*)ML"reset show_question_marks"(*>*)
nipkow@15689
   130
nipkow@17127
   131
subsection {*Variable names\label{sec:varnames}*}
nipkow@16395
   132
nipkow@16395
   133
text{* It sometimes happens that you want to change the name of a
nipkow@16395
   134
variable in a theorem before printing it. This can easily be achieved
nipkow@16395
   135
with the help of Isabelle's instantiation attribute \texttt{where}:
nipkow@16395
   136
@{thm conjI[where P = \<phi> and Q = \<psi>]} is the result of
nipkow@16395
   137
\begin{quote}
nipkow@16395
   138
\verb!@!\verb!{thm conjI[where P = \<phi> and Q = \<psi>]}!
nipkow@16395
   139
\end{quote}
nipkow@16395
   140
To support the ``\_''-notation for irrelevant variables
nipkow@16395
   141
the constant \texttt{DUMMY} has been introduced:
nipkow@16395
   142
@{thm fst_conv[where b = DUMMY]} is produced by
nipkow@16395
   143
\begin{quote}
nipkow@16395
   144
\verb!@!\verb!{thm fst_conv[where b = DUMMY]}!
nipkow@16395
   145
\end{quote}
nipkow@16395
   146
*}
nipkow@16395
   147
nipkow@15337
   148
subsection "Inference rules"
nipkow@15337
   149
nipkow@15342
   150
text{* To print theorems as inference rules you need to include Didier
nipkow@15342
   151
R\'emy's \texttt{mathpartir} package~\cite{mathpartir}
nipkow@15342
   152
for typesetting inference rules in your \LaTeX\ file.
nipkow@15337
   153
nipkow@15689
   154
Writing \verb!@!\verb!{thm[mode=Rule] conjI}! produces
nipkow@15689
   155
@{thm[mode=Rule] conjI}, even in the middle of a sentence.
nipkow@15342
   156
If you prefer your inference rule on a separate line, maybe with a name,
nipkow@15342
   157
\begin{center}
nipkow@15689
   158
@{thm[mode=Rule] conjI} {\sc conjI}
nipkow@15342
   159
\end{center}
nipkow@15342
   160
is produced by
nipkow@15337
   161
\begin{quote}
nipkow@15337
   162
\verb!\begin{center}!\\
nipkow@15689
   163
\verb!@!\verb!{thm[mode=Rule] conjI} {\sc conjI}!\\
nipkow@15337
   164
\verb!\end{center}!
nipkow@15337
   165
\end{quote}
nipkow@15342
   166
It is not recommended to use the standard \texttt{display} attribute
nipkow@15342
   167
together with \texttt{Rule} because centering does not work and because
nipkow@15342
   168
the line breaking mechanisms of \texttt{display} and \texttt{mathpartir} can
nipkow@15342
   169
clash.
nipkow@15342
   170
nipkow@15337
   171
Of course you can display multiple rules in this fashion:
nipkow@15337
   172
\begin{quote}
nipkow@15337
   173
\verb!\begin{center}\isastyle!\\
nipkow@15689
   174
\verb!@!\verb!{thm[mode=Rule] conjI} {\sc conjI} \\[1ex]!\\
nipkow@15689
   175
\verb!@!\verb!{thm[mode=Rule] conjE} {\sc disjI$_1$} \qquad!\\
nipkow@15689
   176
\verb!@!\verb!{thm[mode=Rule] disjE} {\sc disjI$_2$}!\\
nipkow@15337
   177
\verb!\end{center}!
nipkow@15337
   178
\end{quote}
nipkow@15337
   179
yields
nipkow@15337
   180
\begin{center}\isastyle
nipkow@15689
   181
@{thm[mode=Rule] conjI} {\sc conjI} \\[1ex]
nipkow@15689
   182
@{thm[mode=Rule] disjI1} {\sc disjI$_1$} \qquad
nipkow@15689
   183
@{thm[mode=Rule] disjI2} {\sc disjI$_2$}
nipkow@15337
   184
\end{center}
nipkow@15337
   185
Note that we included \verb!\isastyle! to obtain
nipkow@15337
   186
the smaller font that otherwise comes only with \texttt{display}.
nipkow@15337
   187
nipkow@15342
   188
The \texttt{mathpartir} package copes well if there are too many
nipkow@15342
   189
premises for one line:
nipkow@15342
   190
\begin{center}
nipkow@15342
   191
@{prop[mode=Rule] "\<lbrakk> A \<longrightarrow> B; B \<longrightarrow> C; C \<longrightarrow> D; D \<longrightarrow> E; E \<longrightarrow> F; F \<longrightarrow> G;
nipkow@15342
   192
 G \<longrightarrow> H; H \<longrightarrow> I; I \<longrightarrow> J; J \<longrightarrow> K \<rbrakk> \<Longrightarrow> A \<longrightarrow> K"}
nipkow@15342
   193
\end{center}
nipkow@15342
   194
nipkow@15471
   195
Limitations: 1. Premises and conclusion must each not be longer than
nipkow@15471
   196
the line.  2. Premises that are @{text"\<Longrightarrow>"}-implications are again
nipkow@15471
   197
displayed with a horizontal line, which looks at least unusual.
nipkow@15471
   198
nipkow@15337
   199
*}
nipkow@15342
   200
nipkow@15342
   201
subsection{*If-then*}
nipkow@15342
   202
nipkow@15342
   203
text{* If you prefer a fake ``natural language'' style you can produce
nipkow@15342
   204
the body of
nipkow@15342
   205
\newtheorem{theorem}{Theorem}
nipkow@15342
   206
\begin{theorem}
nipkow@15689
   207
@{thm[mode=IfThen] le_trans}
nipkow@15342
   208
\end{theorem}
nipkow@15342
   209
by typing
nipkow@15342
   210
\begin{quote}
nipkow@15689
   211
\verb!@!\verb!{thm[mode=IfThen] le_trans}!
nipkow@15342
   212
\end{quote}
nipkow@15342
   213
nipkow@15342
   214
In order to prevent odd line breaks, the premises are put into boxes.
nipkow@15342
   215
At times this is too drastic:
nipkow@15342
   216
\begin{theorem}
nipkow@15342
   217
@{prop[mode=IfThen] "longpremise \<Longrightarrow> longerpremise \<Longrightarrow> P(f(f(f(f(f(f(f(f(f(x)))))))))) \<Longrightarrow> longestpremise \<Longrightarrow> conclusion"}
nipkow@15342
   218
\end{theorem}
nipkow@16153
   219
In which case you should use \texttt{IfThenNoBox} instead of
nipkow@16153
   220
\texttt{IfThen}:
nipkow@15342
   221
\begin{theorem}
nipkow@15342
   222
@{prop[mode=IfThenNoBox] "longpremise \<Longrightarrow> longerpremise \<Longrightarrow> P(f(f(f(f(f(f(f(f(f(x)))))))))) \<Longrightarrow> longestpremise \<Longrightarrow> conclusion"}
nipkow@15342
   223
\end{theorem}
kleing@15366
   224
*}
nipkow@15342
   225
haftmann@16166
   226
subsection{* Doing it yourself\label{sec:yourself}*}
nipkow@16153
   227
nipkow@16153
   228
text{* If for some reason you want or need to present theorems your
nipkow@16153
   229
own way, you can extract the premises and the conclusion explicitly
nipkow@16153
   230
and combine them as you like:
nipkow@16153
   231
\begin{itemize}
haftmann@16167
   232
\item \verb!@!\verb!{thm_style prem1! $thm$\verb!}!
haftmann@16167
   233
prints premise 1 of $thm$ (and similarly up to \texttt{prem9}).
haftmann@16165
   234
\item \verb!@!\verb!{thm_style concl! $thm$\verb!}!
nipkow@16153
   235
prints the conclusion of $thm$.
nipkow@16153
   236
\end{itemize}
haftmann@16167
   237
For example, ``from @{thm_style prem2 conjI} and
haftmann@16167
   238
@{thm_style prem1 conjI} we conclude @{thm_style concl conjI}''
nipkow@16153
   239
is produced by
nipkow@16153
   240
\begin{quote}
nipkow@16175
   241
\verb!from !\verb!@!\verb!{thm_style prem2 conjI}! \verb!and !\verb!@!\verb!{thm_style prem1 conjI}!\\
haftmann@16165
   242
\verb!we conclude !\verb!@!\verb!{thm_style concl conjI}!
nipkow@16153
   243
\end{quote}
nipkow@16153
   244
Thus you can rearrange or hide premises and typeset the theorem as you like.
nipkow@16153
   245
The \verb!thm_style! antiquotation is a general mechanism explained
nipkow@16153
   246
in \S\ref{sec:styles}.
nipkow@16153
   247
*}
nipkow@16153
   248
kleing@15366
   249
subsection "Patterns"
kleing@15366
   250
kleing@15366
   251
text {*
kleing@15366
   252
nipkow@17127
   253
  In \S\ref{sec:varnames} we shows how to create patterns containing
nipkow@17127
   254
  ``@{term DUMMY}''.
kleing@15366
   255
  You can drive this game even further and extend the syntax of let
kleing@15366
   256
  bindings such that certain functions like @{term fst}, @{term hd}, 
kleing@15368
   257
  etc.\ are printed as patterns. \texttt{OptionalSugar} provides the
kleing@15368
   258
  following:
kleing@15366
   259
  
kleing@15366
   260
  \begin{center}
kleing@15366
   261
  \begin{tabular}{l@ {~~produced by~~}l}
kleing@15366
   262
  @{term "let x = fst p in t"} & \verb!@!\verb!{term "let x = fst p in t"}!\\
kleing@15366
   263
  @{term "let x = snd p in t"} & \verb!@!\verb!{term "let x = snd p in t"}!\\
kleing@15366
   264
  @{term "let x = hd xs in t"} & \verb!@!\verb!{term "let x = hd xs in t"}!\\
kleing@15366
   265
  @{term "let x = tl xs in t"} & \verb!@!\verb!{term "let x = tl xs in t"}!\\
kleing@15366
   266
  @{term "let x = the y in t"} & \verb!@!\verb!{term "let x = the y in t"}!\\
kleing@15366
   267
  \end{tabular}
kleing@15366
   268
  \end{center}
kleing@15366
   269
*}
kleing@15366
   270
nipkow@16155
   271
section "Proofs"
kleing@15366
   272
kleing@15366
   273
text {*
kleing@15367
   274
  Full proofs, even if written in beautiful Isar style, are likely to
kleing@15366
   275
  be too long and detailed to be included in conference papers, but
kleing@15366
   276
  some key lemmas might be of interest.
kleing@15366
   277
kleing@15366
   278
  It is usually easiest to put them in figures like the one in Fig.\
kleing@15366
   279
  \ref{fig:proof}. This was achieved with the \isakeyword{text\_raw}
kleing@15366
   280
  command:
kleing@15366
   281
*}
kleing@15366
   282
text_raw {*
kleing@15366
   283
  \begin{figure}
kleing@15366
   284
  \begin{center}\begin{minipage}{0.6\textwidth}  
kleing@15428
   285
  \isastyle\isamarkuptrue
kleing@15366
   286
*}
kleing@15366
   287
lemma True
kleing@15366
   288
proof -
kleing@15366
   289
  -- "pretty trivial"
kleing@15366
   290
  show True by force
kleing@15366
   291
qed
kleing@15428
   292
text_raw {*    
kleing@15366
   293
  \end{minipage}\end{center}
kleing@15366
   294
  \caption{Example proof in a figure.}\label{fig:proof}
kleing@15366
   295
  \end{figure}
kleing@15366
   296
*}
kleing@15366
   297
text {*
kleing@15366
   298
kleing@15366
   299
\begin{quote}
kleing@15366
   300
\small
kleing@15366
   301
\verb!text_raw {!\verb!*!\\
kleing@15366
   302
\verb!  \begin{figure}!\\
kleing@15366
   303
\verb!  \begin{center}\begin{minipage}{0.6\textwidth}!\\
kleing@15428
   304
\verb!  \isastyle\isamarkuptrue!\\
kleing@15366
   305
\verb!*!\verb!}!\\
kleing@15366
   306
\verb!lemma True!\\
kleing@15366
   307
\verb!proof -!\\
kleing@15366
   308
\verb!  -- "pretty trivial"!\\
kleing@15366
   309
\verb!  show True by force!\\
kleing@15366
   310
\verb!qed!\\
kleing@15366
   311
\verb!text_raw {!\verb!*!\\
kleing@15366
   312
\verb!  \end{minipage}\end{center}!\\
kleing@15366
   313
\verb!  \caption{Example proof in a figure.}\label{fig:proof}!\\
kleing@15366
   314
\verb!  \end{figure}!\\
kleing@15366
   315
\verb!*!\verb!}!
kleing@15366
   316
\end{quote}
kleing@15366
   317
  
nipkow@15342
   318
*}
nipkow@15342
   319
nipkow@16155
   320
section {*Styles\label{sec:styles}*}
haftmann@15917
   321
haftmann@15917
   322
text {*
nipkow@15953
   323
  The \verb!thm! antiquotation works nicely for single theorems, but
haftmann@15917
   324
  sets of equations as used in definitions are more difficult to
haftmann@16040
   325
  typeset nicely: people tend to prefer aligned @{text "="} signs.
haftmann@15917
   326
haftmann@15917
   327
  To deal with such cases where it is desirable to dive into the structure
haftmann@16040
   328
  of terms and theorems, Isabelle offers antiquotations featuring
haftmann@15917
   329
  ``styles'':
haftmann@15917
   330
haftmann@15917
   331
    \begin{quote}
haftmann@15917
   332
    \verb!@!\verb!{thm_style stylename thm}!\\
haftmann@15917
   333
    \verb!@!\verb!{term_style stylename term}!
haftmann@15917
   334
    \end{quote}
haftmann@15917
   335
haftmann@16040
   336
  A ``style'' is a transformation of propositions. There are predefined
webertj@21558
   337
  styles, namely \verb!lhs! and \verb!rhs!, \verb!prem1! up to \verb!prem9!, and \verb!concl!.
haftmann@16166
   338
  For example, 
kleing@16076
   339
  the output
haftmann@15917
   340
  \begin{center}
haftmann@15917
   341
  \begin{tabular}{l@ {~~@{text "="}~~}l}
haftmann@15917
   342
  @{thm_style lhs foldl_Nil} & @{thm_style rhs foldl_Nil}\\
haftmann@15917
   343
  @{thm_style lhs foldl_Cons} & @{thm_style rhs foldl_Cons}
haftmann@15917
   344
  \end{tabular}
haftmann@15917
   345
  \end{center}
haftmann@15917
   346
  is produced by the following code:
haftmann@15917
   347
  \begin{quote}
haftmann@15917
   348
    \verb!\begin{center}!\\
haftmann@15917
   349
    \verb!\begin{tabular}{l@ {~~!\verb!@!\verb!{text "="}~~}l}!\\
haftmann@15917
   350
    \verb!@!\verb!{thm_style lhs foldl_Nil} & @!\verb!{thm_style rhs foldl_Nil}!\\
haftmann@15917
   351
    \verb!@!\verb!{thm_style lhs foldl_Cons} & @!\verb!{thm_style rhs foldl_Cons}!\\
haftmann@15917
   352
    \verb!\end{tabular}!\\
haftmann@15917
   353
    \verb!\end{center}!
haftmann@15917
   354
  \end{quote}
haftmann@15917
   355
  Note the space between \verb!@! and \verb!{! in the tabular argument.
haftmann@15917
   356
  It prevents Isabelle from interpreting \verb!@ {~~...~~}! 
kleing@16076
   357
  as an antiquotation. The styles \verb!lhs! and \verb!rhs!
haftmann@16040
   358
  extract the left hand side (or right hand side respectivly) from the
kleing@16076
   359
  conclusion of propositions consisting of a binary operator
haftmann@16040
   360
  (e.~g.~@{text "="}, @{text "\<equiv>"}, @{text "<"}).
haftmann@15917
   361
haftmann@16165
   362
  Likewise, \verb!concl! may be used as a style to show just the
kleing@16076
   363
  conclusion of a proposition. For example, take \verb!hd_Cons_tl!:
haftmann@16040
   364
  \begin{center}
haftmann@17031
   365
    @{thm [show_types] hd_Cons_tl}
haftmann@16040
   366
  \end{center}
haftmann@16040
   367
  To print just the conclusion,
haftmann@15917
   368
  \begin{center}
haftmann@17031
   369
    @{thm_style [show_types] concl hd_Cons_tl}
haftmann@15917
   370
  \end{center}
haftmann@16040
   371
  type
haftmann@15917
   372
  \begin{quote}
haftmann@15917
   373
    \verb!\begin{center}!\\
haftmann@17031
   374
    \verb!@!\verb!{thm_style [show_types] concl hd_Cons_tl}!\\
haftmann@15917
   375
    \verb!\end{center}!
haftmann@15917
   376
  \end{quote}
nipkow@17127
   377
  Beware that any options must be placed \emph{before}
haftmann@17031
   378
  the name of the style, as in this example.
haftmann@17031
   379
haftmann@16166
   380
  Further use cases can be found in \S\ref{sec:yourself}.
haftmann@16166
   381
nipkow@15953
   382
  If you are not afraid of ML, you may also define your own styles.
haftmann@15960
   383
  A style is implemented by an ML function of type
haftmann@15960
   384
  \verb!Proof.context -> term -> term!.
haftmann@15960
   385
  Have a look at the following example:
haftmann@15960
   386
haftmann@16040
   387
*}
nipkow@16075
   388
(*<*)
haftmann@16040
   389
setup {*
haftmann@16040
   390
let
haftmann@16040
   391
  fun my_concl ctxt = Logic.strip_imp_concl
wenzelm@18708
   392
  in TermStyle.add_style "my_concl" my_concl
haftmann@16040
   393
end;
haftmann@16040
   394
*}
nipkow@16075
   395
(*>*)
haftmann@16040
   396
text {*
haftmann@16040
   397
haftmann@15917
   398
  \begin{quote}
haftmann@15917
   399
    \verb!setup {!\verb!*!\\
haftmann@15917
   400
    \verb!let!\\
haftmann@16040
   401
    \verb!  fun my_concl ctxt = Logic.strip_imp_concl!\\
wenzelm@18708
   402
    \verb!  in TermStyle.add_style "my_concl" my_concl!\\
haftmann@15917
   403
    \verb!end;!\\
haftmann@15917
   404
    \verb!*!\verb!}!\\
haftmann@15917
   405
  \end{quote}
haftmann@15960
   406
kleing@16076
   407
  \noindent
haftmann@16165
   408
  This example shows how the \verb!concl! style is implemented
kleing@16076
   409
  and may be used as as a ``copy-and-paste'' pattern to write your own styles.
haftmann@15960
   410
kleing@16076
   411
  The code should go into your theory file, separate from the \LaTeX\ text.
haftmann@16040
   412
  The \verb!let! expression avoids polluting the
haftmann@15960
   413
  ML global namespace. Each style receives the current proof context
kleing@16076
   414
  as first argument; this is helpful in situations where the
kleing@16076
   415
  style has some object-logic specific behaviour for example.
haftmann@15960
   416
haftmann@15960
   417
  The mapping from identifier name to the style function
nipkow@17123
   418
  is done by the @{ML TermStyle.add_style} expression which expects the desired
haftmann@15960
   419
  style name and the style function as arguments.
haftmann@15960
   420
  
haftmann@15960
   421
  After this \verb!setup!,
haftmann@16040
   422
  there will be a new style available named \verb!my_concl!, thus allowing
haftmann@16040
   423
  antiquoations like \verb!@!\verb!{thm_style my_concl hd_Cons_tl}!
haftmann@16040
   424
  yielding @{thm_style my_concl hd_Cons_tl}.
haftmann@15917
   425
haftmann@15917
   426
*}
haftmann@15917
   427
nipkow@15337
   428
(*<*)
nipkow@15337
   429
end
nipkow@16175
   430
(*>*)