src/HOL/Isar_examples/document/proof.sty
changeset 7833 f5288e4b95d1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Isar_examples/document/proof.sty	Mon Oct 11 20:44:23 1999 +0200
@@ -0,0 +1,254 @@
+%       proof.sty       (Proof Figure Macros)
+%
+%       version 1.0
+%       October 13, 1990
+%       Copyright (C) 1990 Makoto Tatsuta (tatsuta@riec.tohoku.ac.jp)
+%
+% This program is free software; you can redistribute it or modify
+% it under the terms of the GNU General Public License as published by
+% the Free Software Foundation; either versions 1, or (at your option)
+% any later version.
+%
+% This program is distributed in the hope that it will be useful
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+% GNU General Public License for more details.
+%
+%       Usage:
+%               In \documentstyle, specify an optional style `proof', say,
+%                       \documentstyle[proof]{article}.
+%
+%       The following macros are available:
+%
+%       In all the following macros, all the arguments such as
+%       <Lowers> and <Uppers> are processed in math mode.
+%
+%       \infer<Lower><Uppers>
+%               draws an inference.
+%
+%               Use & in <Uppers> to delimit upper formulae.
+%               <Uppers> consists more than 0 formulae.
+%
+%               \infer returns \hbox{ ... } or \vbox{ ... } and
+%               sets \@LeftOffset and \@RightOffset globally.
+%
+%       \infer[<Label>]<Lower><Uppers>
+%               draws an inference labeled with <Label>.
+%
+%       \infer*<Lower><Uppers>
+%               draws a many step deduction.
+%
+%       \infer*[<Label>]<Lower><Uppers>
+%               draws a many step deduction labeled with <Label>.
+%
+%       \deduce<Lower><Uppers>
+%               draws an inference without a rule.
+%
+%       \deduce[<Proof>]<Lower><Uppers>
+%               draws a many step deduction with a proof name.
+%
+%       Example:
+%               If you want to write
+%                           B C
+%                          -----
+%                      A     D
+%                     ----------
+%                         E
+%       use
+%               \infer{E}{
+%                       A
+%                       &
+%                       \infer{D}{B & C}
+%               }
+%
+
+%       Style Parameters
+
+\newdimen\inferLineSkip         \inferLineSkip=2pt
+\newdimen\inferLabelSkip        \inferLabelSkip=5pt
+\def\inferTabSkip{\quad}
+
+%       Variables
+
+\newdimen\@LeftOffset   % global
+\newdimen\@RightOffset  % global
+\newdimen\@SavedLeftOffset      % safe from users
+
+\newdimen\UpperWidth
+\newdimen\LowerWidth
+\newdimen\LowerHeight
+\newdimen\UpperLeftOffset
+\newdimen\UpperRightOffset
+\newdimen\UpperCenter
+\newdimen\LowerCenter
+\newdimen\UpperAdjust
+\newdimen\RuleAdjust
+\newdimen\LowerAdjust
+\newdimen\RuleWidth
+\newdimen\HLabelAdjust
+\newdimen\VLabelAdjust
+\newdimen\WidthAdjust
+
+\newbox\@UpperPart
+\newbox\@LowerPart
+\newbox\@LabelPart
+\newbox\ResultBox
+
+%       Flags
+
+\newif\if@inferRule     % whether \@infer draws a rule.
+\newif\if@ReturnLeftOffset      % whether \@infer returns \@LeftOffset.
+\newif\if@MathSaved     % whether inner math mode where \infer or
+                        % \deduce appears.
+
+%       Special Fonts
+
+\def\DeduceSym{\vtop{\baselineskip4\p@ \lineskiplimit\z@
+    \vbox{\hbox{.}\hbox{.}\hbox{.}}\hbox{.}}}
+
+%       Math Save Macros
+%
+%       \@SaveMath is called in the very begining of toplevel macros
+%       which are \infer and \deduce.
+%       \@RestoreMath is called in the very last before toplevel macros end.
+%       Remark \infer and \deduce ends calling \@infer.
+
+%\def\@SaveMath{\@MathSavedfalse \ifmmode \ifinner
+%        \relax $\relax \@MathSavedtrue \fi\fi }
+%
+%\def\@RestoreMath{\if@MathSaved \relax $\relax\fi }
+
+\def\@SaveMath{\relax}
+\def\@RestoreMath{\relax}
+
+
+%       Macros
+
+\def\@ifEmpty#1#2#3{\def\@tempa{\@empty}\def\@tempb{#1}\relax
+        \ifx \@tempa \@tempb #2\else #3\fi }
+
+\def\infer{\@SaveMath \@ifnextchar *{\@inferSteps}{\@inferOneStep}}
+
+\def\@inferOneStep{\@inferRuletrue
+        \@ifnextchar [{\@infer}{\@infer[\@empty]}}
+
+\def\@inferSteps*{\@ifnextchar [{\@@inferSteps}{\@@inferSteps[\@empty]}}
+
+\def\@@inferSteps[#1]{\@deduce{#1}[\DeduceSym]}
+
+\def\deduce{\@SaveMath \@ifnextchar [{\@deduce{\@empty}}
+        {\@inferRulefalse \@infer[\@empty]}}
+
+%       \@deduce<Proof Label>[<Proof>]<Lower><Uppers>
+
+\def\@deduce#1[#2]#3#4{\@inferRulefalse
+        \@infer[\@empty]{#3}{\@SaveMath \@infer[{#1}]{#2}{#4}}}
+
+%       \@infer[<Label>]<Lower><Uppers>
+%               If \@inferRuletrue, draws a rule and <Label> is right to
+%               a rule.
+%               Otherwise, draws no rule and <Label> is right to <Lower>.
+
+\def\@infer[#1]#2#3{\relax
+% Get parameters
+        \if@ReturnLeftOffset \else \@SavedLeftOffset=\@LeftOffset \fi
+        \setbox\@LabelPart=\hbox{$#1$}\relax
+        \setbox\@LowerPart=\hbox{$#2$}\relax
+%
+        \global\@LeftOffset=0pt
+        \setbox\@UpperPart=\vbox{\tabskip=0pt \halign{\relax
+                \global\@RightOffset=0pt \@ReturnLeftOffsettrue $##$&&
+                \inferTabSkip
+                \global\@RightOffset=0pt \@ReturnLeftOffsetfalse $##$\cr
+                #3\cr}}\relax
+%                       Here is a little trick.
+%                       \@ReturnLeftOffsettrue(false) influences on \infer or
+%                       \deduce placed in ## locally
+%                       because of \@SaveMath and \@RestoreMath.
+        \UpperLeftOffset=\@LeftOffset
+        \UpperRightOffset=\@RightOffset
+% Calculate Adjustments
+        \LowerWidth=\wd\@LowerPart
+        \LowerHeight=\ht\@LowerPart
+        \LowerCenter=0.5\LowerWidth
+%
+        \UpperWidth=\wd\@UpperPart \advance\UpperWidth by -\UpperLeftOffset
+        \advance\UpperWidth by -\UpperRightOffset
+        \UpperCenter=\UpperLeftOffset
+        \advance\UpperCenter by 0.5\UpperWidth
+%
+        \ifdim \UpperWidth > \LowerWidth
+                % \UpperCenter > \LowerCenter
+        \UpperAdjust=0pt
+        \RuleAdjust=\UpperLeftOffset
+        \LowerAdjust=\UpperCenter \advance\LowerAdjust by -\LowerCenter
+        \RuleWidth=\UpperWidth
+        \global\@LeftOffset=\LowerAdjust
+%
+        \else   % \UpperWidth <= \LowerWidth
+        \ifdim \UpperCenter > \LowerCenter
+%
+        \UpperAdjust=0pt
+        \RuleAdjust=\UpperCenter \advance\RuleAdjust by -\LowerCenter
+        \LowerAdjust=\RuleAdjust
+        \RuleWidth=\LowerWidth
+        \global\@LeftOffset=\LowerAdjust
+%
+        \else   % \UpperWidth <= \LowerWidth
+                % \UpperCenter <= \LowerCenter
+%
+        \UpperAdjust=\LowerCenter \advance\UpperAdjust by -\UpperCenter
+        \RuleAdjust=0pt
+        \LowerAdjust=0pt
+        \RuleWidth=\LowerWidth
+        \global\@LeftOffset=0pt
+%
+        \fi\fi
+% Make a box
+        \if@inferRule
+%
+        \setbox\ResultBox=\vbox{
+                \moveright \UpperAdjust \box\@UpperPart
+                \nointerlineskip \kern\inferLineSkip
+                \moveright \RuleAdjust \vbox{\hrule width\RuleWidth}\relax
+                \nointerlineskip \kern\inferLineSkip
+                \moveright \LowerAdjust \box\@LowerPart }\relax
+%
+        \@ifEmpty{#1}{}{\relax
+%
+        \HLabelAdjust=\wd\ResultBox     \advance\HLabelAdjust by -\RuleAdjust
+        \advance\HLabelAdjust by -\RuleWidth
+        \WidthAdjust=\HLabelAdjust
+        \advance\WidthAdjust by -\inferLabelSkip
+        \advance\WidthAdjust by -\wd\@LabelPart
+        \ifdim \WidthAdjust < 0pt \WidthAdjust=0pt \fi
+%
+        \VLabelAdjust=\dp\@LabelPart
+        \advance\VLabelAdjust by -\ht\@LabelPart
+        \VLabelAdjust=0.5\VLabelAdjust  \advance\VLabelAdjust by \LowerHeight
+        \advance\VLabelAdjust by \inferLineSkip
+%
+        \setbox\ResultBox=\hbox{\box\ResultBox
+                \kern -\HLabelAdjust \kern\inferLabelSkip
+                \raise\VLabelAdjust \box\@LabelPart \kern\WidthAdjust}\relax
+%
+        }\relax % end @ifEmpty
+%
+        \else % \@inferRulefalse
+%
+        \setbox\ResultBox=\vbox{
+                \moveright \UpperAdjust \box\@UpperPart
+                \nointerlineskip \kern\inferLineSkip
+                \moveright \LowerAdjust \hbox{\unhbox\@LowerPart
+                        \@ifEmpty{#1}{}{\relax
+                        \kern\inferLabelSkip \unhbox\@LabelPart}}}\relax
+        \fi
+%
+        \global\@RightOffset=\wd\ResultBox
+        \global\advance\@RightOffset by -\@LeftOffset
+        \global\advance\@RightOffset by -\LowerWidth
+        \if@ReturnLeftOffset \else \global\@LeftOffset=\@SavedLeftOffset \fi
+%
+        \box\ResultBox
+        \@RestoreMath
+}