TEX by topic: a TEXnician's reference

287 Pages·1992·1.301 MB·English

by  Victor Eijkhout

T X BY TOPIC, A T XNICIAN’S REFERENCE
E E
VICTOREIJKHOUT∗
ELECTRONICVERSION1.0,DECEMBER2001
∗ This is – apart from minor changes – the full text of the book TEX by Topic, copyright 1991-
2001VictorEijkhout.Thisbookwasprintedin1991byAddison-WesleyUK,ISBN0-201-56882-9,
reprinted in 1993. This book may be copied; the pdf file of this book may be printed and given
away,anditmaybeincludedinarchivesandonwebsites;thebookmaybedistributedinunaltered
formbothonpaperandelectronicmedia.Youarenotallowedtomakeanychangestothefileorto
reverseengineeritssource;youarenotallowedtochargeforitsdistribution–whetherinphysicalor
electronicform–beyondreasonablematerialcosts.
Ifyouhavecommentsorwanttoexpressyourappreciationthatyouaregettingthisbookthatformerly
soldfor≈$30forfree,pleasevisithttp://www.eijkhout.net/tbt/.Ifyoualreadymadeadonation,thank
you.Youareacredittoyourspecies.
Contents
1 TheStructureoftheTEXProcessor 1
1.1 FourTEXprocessors 1
1.2 Theinputprocessor 2
1.2.1 Characterinput 2
1.2.2 Two-levelinputprocessing 2
1.3 Theexpansionprocessor 3
1.3.1 Theprocessofexpansion 3
1.3.2 Specialcases:\expandafter,\noexpand,and\the 3
1.3.3 Bracesintheexpansionprocessor 4
1.4 Theexecutionprocessor 4
1.5 Thevisualprocessor 5
1.6 Examples 5
1.6.1 Skippedspaces 5
1.6.2 Internalquantitiesandtheirrepresentations 6
2 CategoryCodes
andInternalStates 7
2.1 Introduction 7
2.2 Initialprocessing 7
2.3 Categorycodes 8
2.4 Fromcharacterstotokens 10
2.5 Theinputprocessorasafinitestateautomaton 10
2.5.1 StateN:newline 10
2.5.2 StateS:skippingspaces 10
2.5.3 StateM:middleofline 10
2.6 Accessingthefullcharacterset 11
2.7 Transitionsbetweeninternalstates 11
2.7.1 0:escapecharacter 11
2.7.2 1–4,7–8,11–13:non-blankcharacters 12
2.7.3 5:endofline 12
2.7.4 6:parameter 12
2.7.5 7:superscript 12
2.7.6 9:ignoredcharacter 12
2.7.7 10:space 12
2.7.8 14:comment 12
2.7.9 15:invalid 13
2.8 Lettersandothercharacters 13
2.9 The\partoken 14
2.10 Spaces 14
2.10.1 Skippedspaces 14
2.10.2 Optionalspaces 15
1
Contents
2.10.3 Ignoredandobeyedspaces 15
2.10.4 Moreignoredspaces 16
2.10.5 hspacetokeni 16
2.10.6 Controlspace 17
2.10.7 ‘ ’ 17
2.11 Moreaboutlineends 17
2.11.1 Obeylines 17
2.11.2 Changingthe\endlinechar 18
2.11.3 Moreremarksabouttheend-of-linecharacter 19
2.12 Moreabouttheinputprocessor 19
2.12.1 Theinputprocessorasaseparateprocess 19
2.12.2 Theinputprocessornotasaseparateprocess 20
2.12.3 Recursiveinvocationoftheinputprocessor 20
2.13 The@convention 20
3 Characters 21
3.1 Charactercodes 21
3.2 Controlsequencesforcharacters 22
3.3 Denotingcharacterstobetypeset:\char 22
3.3.1 Implicitcharactertokens:\let 23
3.4 Accents 24
3.5 Testingcharacters 25
3.6 Uppercaseandlowercase 25
3.6.1 Uppercaseandlowercasecodes 25
3.6.2 Uppercaseandlowercasecommands 26
3.6.3 Uppercaseandlowercaseformsofkeywords 26
3.6.4 Creativeuseof\uppercaseand\lowercase 26
3.7 Codesofacharacter 27
3.8 Convertingtokensintocharacterstrings 27
3.8.1 Outputofcontrolsequences 27
3.8.2 Categorycodesofa\string 28
4 Fonts 29
4.1 Fonts 29
4.2 Fontdeclaration 30
4.2.1 Fontsandtfmfiles 30
4.2.2 Queryingthecurrentfontandfontnames 30
4.2.3 \nullfont 31
4.3 Fontinformation 31
4.3.1 Fontdimensions 31
4.3.2 Kerning 32
4.3.3 Italiccorrection 32
4.3.4 Ligatures 32
4.3.5 Boundaryligatures 33
5 Boxes 34
5.1 Boxes 35
5.2 Boxregisters 35
5.2.1 Allocation:\newbox 35
5.2.2 Usage:\setbox,\box,\copy 36
5.2.3 Testing:\ifvoid,\ifhbox,\ifvbox 36
5.2.4 The\lastbox 36
5.3 Naturaldimensionsofboxes 37
2 VictorEijkhout–TEXbyTopic
Contents
5.3.1 Dimensionsofcreatedhorizontalboxes 37
5.3.2 Dimensionsofcreatedverticalboxes 37
5.3.3 Examples 38
5.4 Moreaboutboxdimensions 39
5.4.1 Predetermineddimensions 39
5.4.2 Changestoboxdimensions 40
5.4.3 Movingboxesaround 40
5.4.4 Boxdimensionsandboxplacement 40
5.4.5 Boxesandnegativeglue 41
5.5 Overfullandunderfullboxes 42
5.6 Openingandclosingboxes 42
5.7 Unboxing 43
5.8 Textinboxes 44
5.9 Assortedremarks 44
5.9.1 Forgettingthe\box 44
5.9.2 Special-purposeboxes 45
5.9.3 Theheightofaverticalboxinhorizontalmode 45
5.9.4 Moresubtletieswithverticalboxes 45
5.9.5 Hangingthe\lastboxbackinthelist 46
5.9.6 Dissectingparagraphswith\lastbox 46
6 Horizontaland
VerticalMode 48
6.1 Horizontalandverticalmode 48
6.1.1 Horizontalmode 48
6.1.2 Verticalmode 49
6.2 Horizontalandverticalcommands 49
6.3 Theinternalmodes 50
6.3.1 Restrictedhorizontalmode 50
6.3.2 Internalverticalmode 50
6.4 Boxesandmodes 51
6.4.1 Whatboxdoyouuseinwhatmode? 51
6.4.2 Whatmodeholdsinwhatbox? 51
6.4.3 Mode-dependentbehaviourofboxes 51
6.5 Modesandglue 51
6.6 Migratingmaterial 52
6.6.1 \vadjust 52
6.7 Testingmodes 52
7 Numbers 54
7.1 Numbersandhnumberis 54
7.2 Integers 54
7.2.1 Denotations:integers 55
7.2.2 Denotations:characters 55
7.2.3 Internalintegers 56
7.2.4 Internalintegers:othercodesofacharacter 57
7.2.5 hspecialintegeri 57
7.2.6 Otherinternalquantities:coersiontointeger 57
7.2.7 Trailingspaces 57
7.3 Numbers 57
7.4 Integerregisters 58
7.5 Arithmetic 58
VictorEijkhout–TEXbyTopic 3
Contents
7.5.1 Arithmeticstatements 59
7.5.2 Floating-pointarithmetic 59
7.5.3 Fixed-pointarithmetic 59
7.6 Numbertesting 59
7.7 Remarks 60
7.7.1 Characterconstants 60
7.7.2 Expandingtoofar/howfar 60
8 DimensionsandGlue 62
8.1 Definitionofhglueiandhdimeni 62
8.1.1 Definitionofdimensions 63
8.1.2 Definitionofglue 64
8.1.3 Conversionofhglueitohdimeni 64
8.1.4 Registersfor\dimenand\skip 65
8.1.5 Arithmetic:addition 65
8.1.6 Arithmetic:multiplicationanddivision 66
8.2 Moreaboutdimensions 66
8.2.1 Unitsofmeasurement 66
8.2.2 Dimensiontesting 67
8.2.3 Defineddimensions 67
8.3 Moreaboutglue 67
8.3.1 Stretchandshrink 67
8.3.2 Gluesetting 69
8.3.3 Badness 69
8.3.4 Glueandbreaking 69
8.3.5 \kern 70
8.3.6 Glueandmodes 70
8.3.7 Thelastglueiteminalist:backspacing 70
8.3.8 Examplesofbackspacing 71
8.3.9 Glueintraceoutput 71
9 RulesandLeaders 73
9.1 Rules 73
9.1.1 Ruledimensions 74
9.2 Leaders 74
9.2.1 Ruleleaders 75
9.2.2 Boxleaders 76
9.2.3 Evenlyspacedleaders 76
9.3 Assortedremarks 77
9.3.1 Rulesandmodes 77
9.3.2 Endingaparagraphwithleaders 77
9.3.3 Leadersandboxregisters 77
9.3.4 Outputinleaderboxes 78
9.3.5 Boxleadersintraceoutput 78
9.3.6 Leadersandshiftedmargins 78
10 Grouping 79
10.1 Thegroupingmechanism 79
10.2 Localandglobalassignments 80
10.3 Groupdelimiters 80
10.4 Moreaboutbraces 81
10.4.1 Bracecounters 81
10.4.2 Thebraceasatoken 81
4 VictorEijkhout–TEXbyTopic
Contents
10.4.3 Openandclosingbracecontrolsymbols 82
11 Macros 83
11.1 Introduction 83
11.2 Layoutofamacrodefinition 84
11.3 Prefixes 84
11.4 Thedefinitiontype 85
11.5 Theparametertext 85
11.5.1 Undelimitedparameters 85
11.5.2 Delimitedparameters 86
11.5.3 Exampleswithdelimitedarguments 86
11.5.4 Emptyarguments 88
11.5.5 Themacroparametercharacter 88
11.5.6 Bracedelimiting 89
11.6 Constructionofcontrolsequences 89
11.7 Tokenassignmentsby\letand\futurelet 90
11.7.1 \let 90
11.7.2 \futurelet 90
11.8 Assortedremarks 91
11.8.1 Activecharacters 91
11.8.2 Macrosversusprimitives 91
11.8.3 Tailrecursion 91
11.9 Macrotechniques 92
11.9.1 Unknownnumberofarguments 92
11.9.2 Examiningtheargument 93
11.9.3 Optionalmacroparameterswith\futurelet 95
11.9.4 Two-stepmacros 95
11.9.5 Acommentenvironment 96
12 Expansion 98
12.1 Introduction 98
12.2 Ordinaryexpansion 98
12.3 Reversingexpansionorder 99
12.3.1 Onestepexpansion:\expandafter 99
12.3.2 Totalexpansion:\edef 100
12.3.3 \afterassignment 100
12.3.4 \aftergroup 101
12.4 Preventingexpansion 102
12.4.1 \noexpand 102
12.4.2 \noexpandandactivecharacters 102
12.5 \relax 103
12.5.1 \relaxand\csname 103
12.5.2 Preventingexpansionwith\relax 104
12.5.3 TEXinsertsa\relax 104
12.5.4 Thevalueofnon-macros;\the 105
12.6 Examples 105
12.6.1 Expandingafter 105
12.6.2 Defininginsidean\edef 106
12.6.3 Expansionand\write 107
12.6.4 Controlledexpansioninsidean\edef 108
12.6.5 Multiplepreventionofexpansion 108
12.6.6 Moreexampleswith\relax 108
VictorEijkhout–TEXbyTopic 5
Contents
12.6.7 Example:categorycodesavingandrestoring 109
12.6.8 Combining\aftergroupandboxes 110
12.6.9 Moreexpansion 110
13 Conditionals 111
13.1 Theshapeofconditionals 111
13.2 Characterandcontrolsequencetests 112
13.2.1 \if 112
13.2.2 \ifcat 112
13.2.3 \ifx 112
13.3 Modetests 113
13.4 Numericaltests 113
13.5 Othertests 114
13.5.1 Dimensiontesting 114
13.5.2 Boxtests 114
13.5.3 I/Otests 114
13.5.4 Casestatement 114
13.5.5 Specialtests 115
13.6 The\newifmacro 115
13.7 Evaluationofconditionals 116
13.8 Assortedremarks 117
13.8.1 Thetestgobblesuptokens 117
13.8.2 Thetestwantstogobbleupthe\elseor\fi 117
13.8.3 Macrosandconditionals;theuseof\expandafter 118
13.8.4 Incorrectmatching 119
13.8.5 Conditionalsandgrouping 119
13.8.6 Atrick 120
13.8.7 Moreexamplesofexpansioninconditionals 120
14 TokenLists 123
14.1 Tokenlists 123
14.2 Useoftokenlists 123
14.3 htokenparameteri 124
14.4 Tokenlistregisters 124
14.5 Examples 125
14.5.1 Operationsontokenlists:stackmacros 125
14.5.2 Executingtokenlists 126
15 BaselineDistances 128
15.1 Interlineglue 128
15.2 Theperceiveddepthofboxes 130
15.3 Terminology 130
15.4 Additionalremarks 131
16 ParagraphStart 132
16.1 Whendoesaparagraphstart 132
16.2 Whathappenswhenaparagraphstarts 133
16.3 Assortedremarks 133
16.3.1 Startingaparagraphwithabox 133
16.3.2 Startingaparagraphwithagroup 133
16.4 Examples 134
16.4.1 Stretchableindentation 134
16.4.2 Suppressingindentation 134
16.4.3 Anindentationscheme 134
6 VictorEijkhout–TEXbyTopic
Contents
16.4.4 Aparagraphskipscheme 135
17 ParagraphEnd 137
17.1 Thewayparagraphsend 137
17.1.1 The\parcommandandthe\partoken 138
17.1.2 Paragraphfilling:\parfillskip 138
17.2 Assortedremarks 138
17.2.1 Endingaparagraphandagroupatthesametime 138
17.2.2 Endingaparagraphwith\hfill\break 139
17.2.3 Endingaparagraphwitharule 139
17.2.4 Nopagebreaksinbetweenparagraphs 139
17.2.5 Finite\parfillskip 139
17.2.6 Aprecautionforparagraphsthatdonotindent 140
18 ParagraphShape 141
18.1 Thewidthoftextlines 141
18.2 Shapeparameters 141
18.2.1 Hangingindentation 141
18.2.2 Generalparagraphshapes:\parshape 142
18.3 Assortedremarks 143
18.3.1 Centredlastlines 143
18.3.2 Indentingintothemargin 143
18.3.3 Hangaparagraphfromanobject 144
18.3.4 Anotherapproachtohangingindentation 144
18.3.5 Hangingindentationversus\leftskipshifting 145
18.3.6 Moreexamples 145
19 LineBreaking 146
19.1 Paragraphbreakcostcalculation 147
19.1.1 Badness 147
19.1.2 Penaltiesandotherbreaklocations 147
19.1.3 Demerits 148
19.1.4 Thenumberoflinesofaparagraph 149
19.1.5 Betweenthelines 149
19.2 Theprocessofbreaking 149
19.2.1 Threepasses 150
19.2.2 Tolerancevalues 150
19.3 Discretionaries 150
19.3.1 Hyphensanddiscretionaries 150
19.3.2 Examplesofdiscretionaries 151
19.4 Hyphenation 151
19.4.1 Startofaword 152
19.4.2 Endofaword 152
19.4.3 TEX2versusTEX3 153
19.4.4 Patternsandexceptions 153
19.5 Switchinghyphenationpatterns 153
20 Spacing 155
20.1 Automaticinterwordspace 155
20.2 Userinterwordspace 156
20.3 Controlspaceandtie 156
20.4 Moreonthespacefactor 157
20.4.1 Spacefactorassignments 157
20.4.2 Punctuation 157
VictorEijkhout–TEXbyTopic 7
Contents
20.4.3 Othernon-letters 158
20.4.4 Otherinfluencesonthespacefactor 158
21 CharactersinMathMode 159
21.1 Mathematicalcharacters 159
21.2 Delimiters 160
21.2.1 Delimitercodes 161
21.2.2 Explicit\delimitercommands 161
21.2.3 Findingadelimiter;successors 161
21.2.4 \big,\Big,\bigg,and\Bigg 162
21.3 Radicals 162
21.4 Mathaccents 163
22 FontsinFormulas 164
22.1 Determiningthefontofacharacterinmathmode 164
22.2 Initialfamilysettings 164
22.3 Familydefinition 165
22.4 Somespecificfontchanges 165
22.4.1 ChangethefontofordinarycharactersanduppercaseGreek 165
22.4.2 ChangeuppercaseGreekindependentoftextfont 166
22.4.3 ChangethefontoflowercaseGreek 166
22.5 Assortedremarks 166
22.5.1 Newfontsinformulas 166
22.5.2 Evaluatingthefamilies 167
23 MathematicsTypesetting 168
23.1 Mathmodes 169
23.2 Stylesinmathmode 169
23.2.1 Superscriptsandsubscripts 170
23.2.2 Choiceofstyles 170
23.3 Classesofmathematicalobjects 171
23.4 Largeoperatorsandtheirlimits 171
23.5 Verticalcentring:\vcenter 172
23.6 Mathematicalspacing:muglue 172
23.6.1 Classificationofmuglue 173
23.6.2 Muskipregisters 173
23.6.3 Otherspacesinmathmode 174
23.7 Generalizedfractions 174
23.8 Underlining,overlining 175
23.9 Linebreakinginmathformulas 175
23.10 Fontdimensionsoffamilies2and3 175
23.10.1 Symbolfontattributes 175
23.10.2 Extensionfontattributes 176
23.10.3 Example:subscriptlowering 177
24 DisplayMath 178
24.1 Displays 178
24.2 Displaysinparagraphs 179
24.3 Verticalmaterialarounddisplays 179
24.4 Gluesettingofthedisplaymathlist 180
24.5 Centringthedisplayformula:displacement 180
24.6 Equationnumbers 180
24.6.1 Ordinaryequationnumbers 181
24.6.2 Theequationnumberonaseparateline 181
8 VictorEijkhout–TEXbyTopic
Contents
24.7 Non-centreddisplays 181
25 Alignment 183
25.1 Introduction 183
25.2 Horizontalandverticalalignment 183
25.2.1 Horizontalalignments:\halign 184
25.2.2 Verticalalignments:\valign 184
25.2.3 Materialbetweenthelines:\noalign 184
25.2.4 Sizeofthealignment 185
25.3 Thepreamble 185
25.3.1 Infinitepreambles 185
25.3.2 Bracecountinginpreambles 186
25.3.3 Expansioninthepreamble 186
25.3.4 \tabskip 186
25.4 Thealignment 187
25.4.1 Readinganentry 187
25.4.2 Alternatespecifications:\omit 187
25.4.3 Spanningacrossmultiplecolumns:\span 188
25.4.4 Rulesinalignments 188
25.4.5 Endofaline:\crand\crcr 189
25.5 Example:mathalignments 189
26 PageShape 191
26.1 Thereferencepointforglobalpositioning 191
26.2 \topskip 191
26.3 Pageheightanddepth 192
27 PageBreaking 193
27.1 Thecurrentpageandtherecentcontributions 193
27.2 Activatingthepagebuilder 194
27.3 Pagelengthbookkeeping 194
27.4 Breakpoints 195
27.4.1 Possiblebreakpoints 195
27.4.2 Breakpointpenalties 195
27.4.3 Breakpointcomputation 196
27.5 \vsplit 197
27.6 Examplesofpagebreaking 198
27.6.1 Fillingupapage 198
27.6.2 Determiningthebreakpoint 198
27.6.3 Thepagebuilderafteraparagraph 199
28 OutputRoutines 200
28.1 The\outputtokenlist 200
28.2 Outputand\box255 201
28.3 Marks 201
28.4 Assortedremarks 203
28.4.1 Hazardsinnon-trivialoutputroutines 203
28.4.2 Pagenumbering 203
28.4.3 HeadlinesandfootlinesinplainTEX 203
28.4.4 Example:nowidowlines 203
28.4.5 Example:noindentationtopofpage 204
28.4.6 Moreexamplesofoutputroutines 205
29 Insertions 206
29.1 Insertionitems 206
VictorEijkhout–TEXbyTopic 9