TeX by topic, a texnician's reference

289 Pages·1992·1.349 MB·English

by  Victor Eijkhout

T X BY TOPIC, A T XNICIAN’S REFERENCE
E E
VICTOREIJKHOUT∗
ELECTRONICVERSION1.1,AUGUST2004
∗ This is – apart from minor changes – the full text of the book TEX by Topic, copyright 1991-
2004VictorEijkhout.Thisbookwasprintedin1991byAddison-WesleyUK,ISBN0-201-56882-9,
reprinted in 1993, pdf version first made available 2001. This electronic book may be copied; the
pdffileofthisbookmaybeprintedandgivenaway,anditmaybeincludedinarchivesandonweb
sites; the book may be distributed in unaltered form both on paper and electronic media. You are
notallowedtomakeanychangestothefileortoreverseengineeritssource;youarenotallowed
tochargeforitsdistribution–whetherinphysicalorelectronicform–beyondreasonablematerial
costs.
Ifyouhavecommentsorwanttoexpressyourappreciationthatyouaregettingthisbookthatformerly
soldfor≈$30forfree,pleasevisithttp://www.eijkhout.net/tbt/.Ifyoualreadymadeadonation,thank
you.Youareacredittoyourspecies.
Contents
1 TheStructureoftheTEXProcessor 14
1.1 FourTEXprocessors 14
1.2 Theinputprocessor 15
1.2.1 Characterinput 15
1.2.2 Two-levelinputprocessing 15
1.3 Theexpansionprocessor 16
1.3.1 Theprocessofexpansion 16
1.3.2 Specialcases:\expandafter,\noexpand,and\the 16
1.3.3 Bracesintheexpansionprocessor 17
1.4 Theexecutionprocessor 17
1.5 Thevisualprocessor 18
1.6 Examples 18
1.6.1 Skippedspaces 18
1.6.2 Internalquantitiesandtheirrepresentations 19
2 CategoryCodes
andInternalStates 20
2.1 Introduction 20
2.2 Initialprocessing 20
2.3 Categorycodes 21
2.4 Fromcharacterstotokens 23
2.5 Theinputprocessorasafinitestateautomaton 23
2.5.1 StateN:newline 23
2.5.2 StateS:skippingspaces 23
2.5.3 StateM:middleofline 23
2.6 Accessingthefullcharacterset 24
2.7 Transitionsbetweeninternalstates 24
2.7.1 0:escapecharacter 24
2.7.2 1–4,7–8,11–13:non-blankcharacters 25
2.7.3 5:endofline 25
2.7.4 6:parameter 25
2.7.5 7:superscript 25
2.7.6 9:ignoredcharacter 25
2.7.7 10:space 25
2.7.8 14:comment 25
2.7.9 15:invalid 26
2.8 Lettersandothercharacters 26
2.9 The\partoken 27
2.10 Spaces 27
2.10.1 Skippedspaces 27
2.10.2 Optionalspaces 28
1
Contents
2.10.3 Ignoredandobeyedspaces 28
2.10.4 Moreignoredspaces 29
2.10.5 hspacetokeni 29
2.10.6 Controlspace 30
2.10.7 ‘ ’ 30
2.11 Moreaboutlineends 30
2.11.1 Obeylines 30
2.11.2 Changingthe\endlinechar 31
2.11.3 Moreremarksabouttheend-of-linecharacter 32
2.12 Moreabouttheinputprocessor 32
2.12.1 Theinputprocessorasaseparateprocess 32
2.12.2 Theinputprocessornotasaseparateprocess 33
2.12.3 Recursiveinvocationoftheinputprocessor 33
2.13 The@convention 33
3 Characters 34
3.1 Charactercodes 34
3.2 Controlsequencesforcharacters 35
3.3 Denotingcharacterstobetypeset:\char 35
3.3.1 Implicitcharactertokens:\let 36
3.4 Accents 37
3.5 Testingcharacters 38
3.6 Uppercaseandlowercase 38
3.6.1 Uppercaseandlowercasecodes 38
3.6.2 Uppercaseandlowercasecommands 39
3.6.3 Uppercaseandlowercaseformsofkeywords 39
3.6.4 Creativeuseof\uppercaseand\lowercase 39
3.7 Codesofacharacter 40
3.8 Convertingtokensintocharacterstrings 40
3.8.1 Outputofcontrolsequences 40
3.8.2 Categorycodesofa\string 41
4 Fonts 42
4.1 Fonts 42
4.2 Fontdeclaration 43
4.2.1 Fontsandtfmfiles 43
4.2.2 Queryingthecurrentfontandfontnames 43
4.2.3 \nullfont 44
4.3 Fontinformation 44
4.3.1 Fontdimensions 44
4.3.2 Kerning 45
4.3.3 Italiccorrection 45
4.3.4 Ligatures 45
4.3.5 Boundaryligatures 46
5 Boxes 47
5.1 Boxes 48
5.2 Boxregisters 48
5.2.1 Allocation:\newbox 48
5.2.2 Usage:\setbox,\box,\copy 49
5.2.3 Testing:\ifvoid,\ifhbox,\ifvbox 49
5.2.4 The\lastbox 49
5.3 Naturaldimensionsofboxes 50
2 VictorEijkhout–TEXbyTopic
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5.3.1 Dimensionsofcreatedhorizontalboxes 50
5.3.2 Dimensionsofcreatedverticalboxes 50
5.3.3 Examples 51
5.4 Moreaboutboxdimensions 52
5.4.1 Predetermineddimensions 52
5.4.2 Changestoboxdimensions 53
5.4.3 Movingboxesaround 53
5.4.4 Boxdimensionsandboxplacement 53
5.4.5 Boxesandnegativeglue 54
5.5 Overfullandunderfullboxes 55
5.6 Openingandclosingboxes 55
5.7 Unboxing 56
5.8 Textinboxes 57
5.9 Assortedremarks 57
5.9.1 Forgettingthe\box 57
5.9.2 Special-purposeboxes 58
5.9.3 Theheightofaverticalboxinhorizontalmode 58
5.9.4 Moresubtletieswithverticalboxes 58
5.9.5 Hangingthe\lastboxbackinthelist 59
5.9.6 Dissectingparagraphswith\lastbox 59
6 Horizontaland
VerticalMode 61
6.1 Horizontalandverticalmode 61
6.1.1 Horizontalmode 61
6.1.2 Verticalmode 62
6.2 Horizontalandverticalcommands 62
6.3 Theinternalmodes 63
6.3.1 Restrictedhorizontalmode 63
6.3.2 Internalverticalmode 63
6.4 Boxesandmodes 64
6.4.1 Whatboxdoyouuseinwhatmode? 64
6.4.2 Whatmodeholdsinwhatbox? 64
6.4.3 Mode-dependentbehaviourofboxes 64
6.5 Modesandglue 64
6.6 Migratingmaterial 65
6.6.1 \vadjust 65
6.7 Testingmodes 65
7 Numbers 67
7.1 Numbersandhnumberis 67
7.2 Integers 67
7.2.1 Denotations:integers 68
7.2.2 Denotations:characters 68
7.2.3 Internalintegers 69
7.2.4 Internalintegers:othercodesofacharacter 70
7.2.5 hspecialintegeri 70
7.2.6 Otherinternalquantities:coersiontointeger 70
7.2.7 Trailingspaces 70
7.3 Numbers 70
7.4 Integerregisters 71
7.5 Arithmetic 71
VictorEijkhout–TEXbyTopic 3
Contents
7.5.1 Arithmeticstatements 72
7.5.2 Floating-pointarithmetic 72
7.5.3 Fixed-pointarithmetic 72
7.6 Numbertesting 72
7.7 Remarks 73
7.7.1 Characterconstants 73
7.7.2 Expandingtoofar/howfar 73
8 DimensionsandGlue 75
8.1 Definitionofhglueiandhdimeni 75
8.1.1 Definitionofdimensions 76
8.1.2 Definitionofglue 77
8.1.3 Conversionofhglueitohdimeni 77
8.1.4 Registersfor\dimenand\skip 78
8.1.5 Arithmetic:addition 78
8.1.6 Arithmetic:multiplicationanddivision 79
8.2 Moreaboutdimensions 79
8.2.1 Unitsofmeasurement 79
8.2.2 Dimensiontesting 80
8.2.3 Defineddimensions 80
8.3 Moreaboutglue 80
8.3.1 Stretchandshrink 80
8.3.2 Gluesetting 82
8.3.3 Badness 82
8.3.4 Glueandbreaking 82
8.3.5 \kern 83
8.3.6 Glueandmodes 83
8.3.7 Thelastglueiteminalist:backspacing 83
8.3.8 Examplesofbackspacing 84
8.3.9 Glueintraceoutput 84
9 RulesandLeaders 86
9.1 Rules 86
9.1.1 Ruledimensions 87
9.2 Leaders 87
9.2.1 Ruleleaders 88
9.2.2 Boxleaders 89
9.2.3 Evenlyspacedleaders 89
9.3 Assortedremarks 90
9.3.1 Rulesandmodes 90
9.3.2 Endingaparagraphwithleaders 90
9.3.3 Leadersandboxregisters 90
9.3.4 Outputinleaderboxes 91
9.3.5 Boxleadersintraceoutput 91
9.3.6 Leadersandshiftedmargins 91
10 Grouping 92
10.1 Thegroupingmechanism 92
10.2 Localandglobalassignments 93
10.3 Groupdelimiters 93
10.4 Moreaboutbraces 94
10.4.1 Bracecounters 94
10.4.2 Thebraceasatoken 94
4 VictorEijkhout–TEXbyTopic
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10.4.3 Openandclosingbracecontrolsymbols 95
11 Macros 96
11.1 Introduction 96
11.2 Layoutofamacrodefinition 97
11.3 Prefixes 97
11.4 Thedefinitiontype 98
11.5 Theparametertext 98
11.5.1 Undelimitedparameters 98
11.5.2 Delimitedparameters 99
11.5.3 Exampleswithdelimitedarguments 99
11.5.4 Emptyarguments 101
11.5.5 Themacroparametercharacter 101
11.5.6 Bracedelimiting 102
11.6 Constructionofcontrolsequences 102
11.7 Tokenassignmentsby\letand\futurelet 103
11.7.1 \let 103
11.7.2 \futurelet 103
11.8 Assortedremarks 104
11.8.1 Activecharacters 104
11.8.2 Macrosversusprimitives 104
11.8.3 Tailrecursion 104
11.9 Macrotechniques 105
11.9.1 Unknownnumberofarguments 105
11.9.2 Examiningtheargument 106
11.9.3 Optionalmacroparameterswith\futurelet 108
11.9.4 Two-stepmacros 108
11.9.5 Acommentenvironment 109
12 Expansion 111
12.1 Introduction 111
12.2 Ordinaryexpansion 111
12.3 Reversingexpansionorder 112
12.3.1 Onestepexpansion:\expandafter 112
12.3.2 Totalexpansion:\edef 113
12.3.3 \afterassignment 113
12.3.4 \aftergroup 114
12.4 Preventingexpansion 115
12.4.1 \noexpand 115
12.4.2 \noexpandandactivecharacters 115
12.5 \relax 116
12.5.1 \relaxand\csname 116
12.5.2 Preventingexpansionwith\relax 117
12.5.3 TEXinsertsa\relax 117
12.5.4 Thevalueofnon-macros;\the 118
12.6 Examples 118
12.6.1 Expandingafter 118
12.6.2 Defininginsidean\edef 119
12.6.3 Expansionand\write 120
12.6.4 Controlledexpansioninsidean\edef 121
12.6.5 Multiplepreventionofexpansion 121
12.6.6 Moreexampleswith\relax 121
VictorEijkhout–TEXbyTopic 5
Contents
12.6.7 Example:categorycodesavingandrestoring 122
12.6.8 Combining\aftergroupandboxes 123
12.6.9 Moreexpansion 123
13 Conditionals 124
13.1 Theshapeofconditionals 124
13.2 Characterandcontrolsequencetests 125
13.2.1 \if 125
13.2.2 \ifcat 125
13.2.3 \ifx 125
13.3 Modetests 126
13.4 Numericaltests 126
13.5 Othertests 127
13.5.1 Dimensiontesting 127
13.5.2 Boxtests 127
13.5.3 I/Otests 127
13.5.4 Casestatement 127
13.5.5 Specialtests 128
13.6 The\newifmacro 128
13.7 Evaluationofconditionals 129
13.8 Assortedremarks 130
13.8.1 Thetestgobblesuptokens 130
13.8.2 Thetestwantstogobbleupthe\elseor\fi 130
13.8.3 Macrosandconditionals;theuseof\expandafter 131
13.8.4 Incorrectmatching 132
13.8.5 Conditionalsandgrouping 132
13.8.6 Atrick 133
13.8.7 Moreexamplesofexpansioninconditionals 133
14 TokenLists 136
14.1 Tokenlists 136
14.2 Useoftokenlists 136
14.3 htokenparameteri 137
14.4 Tokenlistregisters 137
14.5 Examples 138
14.5.1 Operationsontokenlists:stackmacros 138
14.5.2 Executingtokenlists 139
15 BaselineDistances 141
15.1 Interlineglue 141
15.2 Theperceiveddepthofboxes 143
15.3 Terminology 143
15.4 Additionalremarks 144
16 ParagraphStart 145
16.1 Whendoesaparagraphstart 145
16.2 Whathappenswhenaparagraphstarts 146
16.3 Assortedremarks 146
16.3.1 Startingaparagraphwithabox 146
16.3.2 Startingaparagraphwithagroup 146
16.4 Examples 147
16.4.1 Stretchableindentation 147
16.4.2 Suppressingindentation 147
16.4.3 Anindentationscheme 147
6 VictorEijkhout–TEXbyTopic
Contents
16.4.4 Aparagraphskipscheme 148
17 ParagraphEnd 150
17.1 Thewayparagraphsend 150
17.1.1 The\parcommandandthe\partoken 151
17.1.2 Paragraphfilling:\parfillskip 151
17.2 Assortedremarks 151
17.2.1 Endingaparagraphandagroupatthesametime 151
17.2.2 Endingaparagraphwith\hfill\break 152
17.2.3 Endingaparagraphwitharule 152
17.2.4 Nopagebreaksinbetweenparagraphs 152
17.2.5 Finite\parfillskip 152
17.2.6 Aprecautionforparagraphsthatdonotindent 153
18 ParagraphShape 154
18.1 Thewidthoftextlines 154
18.2 Shapeparameters 154
18.2.1 Hangingindentation 154
18.2.2 Generalparagraphshapes:\parshape 155
18.3 Assortedremarks 156
18.3.1 Centredlastlines 156
18.3.2 Indentingintothemargin 156
18.3.3 Hangaparagraphfromanobject 157
18.3.4 Anotherapproachtohangingindentation 157
18.3.5 Hangingindentationversus\leftskipshifting 158
18.3.6 Moreexamples 158
19 LineBreaking 159
19.1 Paragraphbreakcostcalculation 160
19.1.1 Badness 160
19.1.2 Penaltiesandotherbreaklocations 160
19.1.3 Demerits 161
19.1.4 Thenumberoflinesofaparagraph 162
19.1.5 Betweenthelines 162
19.2 Theprocessofbreaking 162
19.2.1 Threepasses 163
19.2.2 Tolerancevalues 163
19.3 Discretionaries 163
19.3.1 Hyphensanddiscretionaries 163
19.3.2 Examplesofdiscretionaries 164
19.4 Hyphenation 164
19.4.1 Startofaword 165
19.4.2 Endofaword 165
19.4.3 TEX2versusTEX3 166
19.4.4 Patternsandexceptions 166
19.5 Switchinghyphenationpatterns 166
20 Spacing 168
20.1 Introduction 168
20.2 Automaticinterwordspace 168
20.3 Userinterwordspace 169
20.4 Controlspaceandtie 170
20.5 Moreonthespacefactor 171
20.5.1 Spacefactorassignments 171
VictorEijkhout–TEXbyTopic 7
Contents
20.5.2 Punctuation 171
20.5.3 Othernon-letters 172
20.5.4 Otherinfluencesonthespacefactor 172
21 CharactersinMathMode 173
21.1 Mathematicalcharacters 173
21.2 Delimiters 174
21.2.1 Delimitercodes 175
21.2.2 Explicit\delimitercommands 175
21.2.3 Findingadelimiter;successors 175
21.2.4 \big,\Big,\bigg,and\Bigg 176
21.3 Radicals 176
21.4 Mathaccents 177
22 FontsinFormulas 178
22.1 Determiningthefontofacharacterinmathmode 178
22.2 Initialfamilysettings 178
22.3 Familydefinition 179
22.4 Somespecificfontchanges 179
22.4.1 ChangethefontofordinarycharactersanduppercaseGreek 179
22.4.2 ChangeuppercaseGreekindependentoftextfont 180
22.4.3 ChangethefontoflowercaseGreek 180
22.5 Assortedremarks 180
22.5.1 Newfontsinformulas 180
22.5.2 Evaluatingthefamilies 181
23 MathematicsTypesetting 182
23.1 Mathmodes 183
23.2 Stylesinmathmode 183
23.2.1 Superscriptsandsubscripts 184
23.2.2 Choiceofstyles 184
23.3 Classesofmathematicalobjects 185
23.4 Largeoperatorsandtheirlimits 185
23.5 Verticalcentring:\vcenter 186
23.6 Mathematicalspacing:muglue 186
23.6.1 Classificationofmuglue 187
23.6.2 Muskipregisters 187
23.6.3 Otherspacesinmathmode 188
23.7 Generalizedfractions 188
23.8 Underlining,overlining 189
23.9 Linebreakinginmathformulas 189
23.10 Fontdimensionsoffamilies2and3 189
23.10.1 Symbolfontattributes 189
23.10.2 Extensionfontattributes 190
23.10.3 Example:subscriptlowering 191
24 DisplayMath 192
24.1 Displays 192
24.2 Displaysinparagraphs 193
24.3 Verticalmaterialarounddisplays 193
24.4 Gluesettingofthedisplaymathlist 194
24.5 Centringthedisplayformula:displacement 194
24.6 Equationnumbers 194
24.6.1 Ordinaryequationnumbers 195
8 VictorEijkhout–TEXbyTopic
Contents
24.6.2 Theequationnumberonaseparateline 195
24.7 Non-centreddisplays 195
25 Alignment 197
25.1 Introduction 197
25.2 Horizontalandverticalalignment 197
25.2.1 Horizontalalignments:\halign 198
25.2.2 Verticalalignments:\valign 198
25.2.3 Materialbetweenthelines:\noalign 198
25.2.4 Sizeofthealignment 199
25.3 Thepreamble 199
25.3.1 Infinitepreambles 199
25.3.2 Bracecountinginpreambles 200
25.3.3 Expansioninthepreamble 200
25.3.4 \tabskip 200
25.4 Thealignment 201
25.4.1 Readinganentry 201
25.4.2 Alternatespecifications:\omit 201
25.4.3 Spanningacrossmultiplecolumns:\span 202
25.4.4 Rulesinalignments 202
25.4.5 Endofaline:\crand\crcr 203
25.5 Example:mathalignments 203
26 PageShape 205
26.1 Thereferencepointforglobalpositioning 205
26.2 \topskip 205
26.3 Pageheightanddepth 206
27 PageBreaking 207
27.1 Thecurrentpageandtherecentcontributions 207
27.2 Activatingthepagebuilder 208
27.3 Pagelengthbookkeeping 208
27.4 Breakpoints 209
27.4.1 Possiblebreakpoints 209
27.4.2 Breakpointpenalties 209
27.4.3 Breakpointcomputation 210
27.5 \vsplit 211
27.6 Examplesofpagebreaking 212
27.6.1 Fillingupapage 212
27.6.2 Determiningthebreakpoint 212
27.6.3 Thepagebuilderafteraparagraph 213
28 OutputRoutines 214
28.1 The\outputtokenlist 214
28.2 Outputand\box255 215
28.3 Marks 215
28.4 Assortedremarks 217
28.4.1 Hazardsinnon-trivialoutputroutines 217
28.4.2 Pagenumbering 217
28.4.3 HeadlinesandfootlinesinplainTEX 217
28.4.4 Example:nowidowlines 217
28.4.5 Example:noindentationtopofpage 218
28.4.6 Moreexamplesofoutputroutines 219
29 Insertions 220
VictorEijkhout–TEXbyTopic 9