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1.1 root 1: .\" @(#)m1 6.1 (Berkeley) 4/17/86
2: .\"
3: .pn8
4: .tr |
5: .tr ~|
6: .rm mx
7: .br
8: .ce
9: .ftB
10: .ps+2
11: .rs
12: .\".sp1.0i
13: REFERENCE MANUAL
14: .ftR
15: .ps-2
16: .sp
17: .mh
18: General Explanation
19: .sc
20: Form of input.
21: Input consists of \fItext lines\fR, which are destined to be printed,
22: interspersed with \fIcontrol lines\fR,
23: which set parameters or otherwise control subsequent processing.
24: Control lines begin with a \fIcontrol character\fR\(em\
25: normally \fB.\fR (period) or \fB\'\fR (acute accent)\(em\
26: followed by a one or two character name that specifies
27: a basic \fIrequest\fR or the substitution of
28: a user-defined \fImacro\fR in place of the control line.
29: The control character \fB\'\fR suppresses the \fIbreak\fR function\(em\
30: the forced output of a partially filled line\(em\
31: caused by certain requests.
32: The control character may be separated from the request/macro name by
33: white space (spaces and/or tabs) for \(aesthetic reasons.
34: Names must be followed by either
35: space or newline.
36: Control lines with unrecognized names are ignored.
37: .pg
38: Various special functions may be introduced anywhere in the input by
39: means of an \fIescape\fR character, normally \fB\e\fR.
40: For example, the function
41: \fB\en\fIR\fR
42: causes the interpolation (insertion in place) of the contents of the
43: \fInumber register R\fR
44: in place of the function;
45: here \fIR\fR is either a single character name
46: as in \fB\en\fIx\fR,
47: or left-parenthesis-introduced, two-character name as in \fB\en(\fIxx\fR.
48: .sc
49: Formatter and device resolution.
50: \*(TR internally uses 432 units\(slinch, (for historical reasons, corresponding to
51: the Graphic Systems phototypesetter
52: which had a horizontal resolution of
53: 1\(sl432 inch and a vertical resolution
54: of 1\(sl144 inch.)
55: \*(NR internally uses 240 units\(slinch,
56: corresponding to the least common multiple of the
57: horizontal and vertical resolutions of various
58: typewriter-like output devices.
59: \*(TR rounds horizontal\(slvertical numerical parameter input to its own
60: internal horizontal\(slvertical resolution.
61: \*(NR similarly rounds numerical input to the actual resolution
62: of the output device indicated by the \fB\(miT\fR option
63: (default Model 37 Teletype).
64: .sc
65: Numerical parameter input.
66: Both \*(NR and \*(TR
67: accept numerical input with the scale
68: indicator suffixes
69: shown in the following table,
70: where
71: \fIS\fR is the current type size in points,
72: \fIV\fR is the current vertical line spacing in
73: basic units,
74: and
75: \fIC\fR is a \fInominal character width\fR in basic units.
76: .TS
77: center box;
78: c|c|ls
79: c|c|ll
80: c|l|l|l.
81: Scale Number of basic units
82: Indicator Meaning \*(TR \*(NR
83: _
84: \fBi\fR Inch 432 240
85: \fBc\fR Centimeter 432\(mu50\(sl127 240\(mu50\(sl127
86: \fBP\fR Pica = 1\(sl6 inch 72 240\(sl6
87: \fBm\fR Em = \fIS\fR points 6\(mu\fIS\fR \fIC\fR
88: \fBn\fR En = Em\(sl2 3\(mu\fIS\fR \fIC, same as Em\fR
89: \fBp\fR Point = 1\(sl72 inch 6 240\(sl72
90: \fBu\fR Basic unit 1 1
91: \fBv\fR Vertical line space \fIV\fR \fIV\fR
92: none Default, see below
93: .TE
94: In \*(NR, \fIboth\fR the em and the en are taken to be equal to the \fIC\fR,
95: which is output-device dependent;
96: common values are 1\(sl10 and 1\(sl12 inch.
97: Actual character widths in \*(NR need not be all the same and constructed characters
98: such as \(mi> (\(->) are often extra wide.
99: The default scaling is ems for the horizontally-oriented requests
100: and functions
101: \fBll\fR,
102: \fBin\fR,
103: \fBti\fR,
104: \fBta\fR,
105: \fBlt\fR,
106: \fBpo\fR,
107: \fBmc\fR,
108: \fB\eh\fR,
109: and
110: \fB\el\fR;
111: \fIV\^\fRs
112: for the vertically-oriented requests and functions
113: \fBpl\fR,
114: \fBwh\fR,
115: \fBch\fR,
116: \fBdt\fR,
117: \fBsp\fR,
118: \fBsv\fR,
119: \fBne\fR,
120: \fBrt\fR,
121: \fB\ev\fR,
122: \fB\ex\fR,
123: and
124: \fB\eL\fR;
125: \fBp\fR for the \fBvs\fR request;
126: and \fBu\fR for the requests
127: \fBnr\fR,
128: \fBif\fR,
129: and
130: \fBie\fR.
131: \fIAll\fR other requests ignore any scale indicators.
132: When a number register containing an already appropriately scaled number
133: is interpolated to provide numerical input,
134: the unit scale indicator
135: \fBu\fR may need to be appended to prevent
136: an additional inappropriate default scaling.
137: The number, \fIN\fR, may be specified in decimal-fraction form
138: but the parameter finally stored is rounded to an integer number of basic units.
139: .pg
140: The \fIabsolute position\fR indicator \fB~\fR may be prefixed
141: to a number \fIN\fR
142: to generate the distance to the vertical or horizontal place \fIN\fR.
143: For vertically-oriented requests and functions, \fB~\|\fIN\fR
144: becomes the distance in basic units from the current vertical place on the page or in a \fIdiversion\fR (\(sc7.4)
145: to the vertical place \fIN\fR.
146: For \fIall\fR other requests and functions,
147: \fB~\|\fIN\fR
148: becomes the distance from
149: the current horizontal place on the \fIinput\fR line to the horizontal place \fIN\fR.
150: For example,
151: .x1
152: \&\fB.sp ~\|3.2c\fR
153: .x2
154: will space \fIin the required direction\fR to 3.2 centimeters from the top of the page.
155: .sc
156: .tr &&
157: Numerical expressions.
158: Wherever numerical input is expected, an expression involving parentheses,
159: the arithmetic operators \fB\(pl\fR, \fB\(mi\fR, \fB\(sl\fR, \fB\(**\fR, \fB%\fR (mod),
160: and the logical operators
161: \fB<\fR,
162: \fB>\fR,
163: \fB<\(eq\fR,
164: \fB>\(eq\fR,
165: \fB\(eq\fR (or \fB\(eq\(eq\fR),
166: \fB&\fR\ (and),
167: \fB:\fR\ (or)
168: may be used.
169: Except where controlled by parentheses, evaluation of expressions is left-to-right;
170: there is no operator precedence.
171: In the case of certain requests, an initial \fB\(pl\fR or \fB\(mi\fR is stripped
172: and interpreted as an increment or decrement indicator respectively.
173: In the presence of default scaling, the desired scale indicator must be
174: attached to \fIevery\fR number in an expression
175: for which the desired and default scaling differ.
176: For example,
177: if the number register \fBx\fR contains 2
178: and the current point size is 10,
179: then
180: .br
181: .tr &.
182: .x1
183: .ftB
184: \&.ll (4.25i\(pl\enxP\(pl3)\(sl2u
185: .ftR
186: .x2
187: will set the line length to 1\(sl2 the sum of 4.25 inches \(pl 2 picas \(pl 30 points.
188: .sc
189: Notation.
190: Numerical parameters are indicated in this manual in two ways.
191: \(+-\fIN\fR means that the argument may take the forms \fIN\fR, \(pl\fIN\fR, or \(mi\fIN\fR and
192: that the corresponding effect is to set the affected parameter
193: to \fIN\fR, to increment it by \fIN\fR, or to decrement it by \fIN\fR respectively.
194: Plain \fIN\fR means that an initial algebraic sign is \fInot\fR
195: an increment indicator,
196: but merely the sign of \fIN\fR.
197: Generally, unreasonable numerical input is either ignored
198: or truncated to a reasonable value.
199: For example,
200: most requests expect to set parameters to non-negative
201: values;
202: exceptions are
203: \fBsp\fR,
204: \fBwh\fR,
205: \fBch\fR,
206: \fBnr\fR,
207: and
208: \fBif\fR.
209: The requests
210: \fBps\fR,
211: \fBft\fR,
212: \fBpo\fR,
213: \fBvs\fR,
214: \fBls\fR,
215: \fBll\fR,
216: \fBin\fR,
217: and
218: \fBlt\fR
219: restore the \fIprevious\fR parameter value in the \fIabsence\fR
220: of an argument.
221: .pg
222: Single character arguments are indicated by single lower case letters
223: and
224: one/two character arguments are indicated by a pair of lower case letters.
225: Character string arguments are indicated by multi-character mnemonics.
226: .mh
227: Font and Character Size Control
228: .sc
229: Character set.
230: The \*(TR character set consists of a typesetter-dependent basic
231: character set plus a Special Mathematical Font character
232: set\(emeach having 102 characters.
233: An example of these character sets is shown in the Appendix Table|I.
234: All printable \s-1ASCII\s+1 characters are included,
235: with some on the Special Font.
236: With three exceptions, these \s-1ASCII\s+1 characters are input as themselves,
237: and non-\s-1ASCII\s+1 characters are input in the form \fB\e(\fIxx\fR where
238: \fIxx\fR is a two-character name given in the Appendix Table|II.
239: The three \s-1ASCII\s+1 exceptions are mapped as follows:
240: .TS
241: center box;
242: cs|cs
243: cc|cc
244: cl|cl.
245: \s-1ASCII\s+1 Input Printed by \*(TR
246: Character Name Character Name
247: _
248: \' acute accent ' close quote
249: \` grave accent ` open quote
250: \(mi minus - hyphen
251: .TE
252: .tr ~~
253: The characters
254: \fB\'\fR,
255: \fB\`\fR,
256: and
257: \fB\-\fR
258: may be input
259: by \fB\e\'\fR, \fB\e\`\fR, and \fB\e\-\fR respectively or by their names (Table II).
260: The \s-1ASCII\s+1 characters \fB@\fR, \fB#\fR, \fB"\fR, \fB\(aa\fR, \fB\(ga\fR, \fB<\fR, \fB>\fR, \fB\e\fR, \fB{\fR, \fB}\fR, \fB~\fR, \fB^\fR, and \fB\(ul\fR exist
261: only on the Special Font and are printed as a 1-em space if that font
262: is not mounted.
263: .pg
264: .tr ~|
265: \*(NR understands the entire \*(TR character set,
266: but can in general print only \s-1ASCII\s+1
267: characters,
268: additional characters as may be available on
269: the output device,
270: such characters as may be able to be constructed
271: by overstriking or other combination,
272: and those that can reasonably be mapped
273: into other printable characters.
274: The exact behavior is determined by a driving
275: table prepared for each device.
276: The characters
277: \fB\'\fR,
278: \fB\`\fR,
279: and
280: \fB\(ul\fR
281: print
282: as themselves.
283: .sc
284: Fonts.
285: The default mounted fonts are
286: Times Roman (\fBR\fR),
287: Times Italic (\fBI\fR),
288: Times Bold (\fBB\fR),
289: and the Special Mathematical Font (\fBS\fR)
290: on physical typesetter positions 1, 2, 3, and 4 respectively.
291: These fonts are used in this document.
292: The \fIcurrent\fR font, initially Roman, may be changed
293: (among the mounted fonts)
294: by use of the \fBft\fR request,
295: or by imbedding at any desired point
296: either \fB\ef\fIx\fR, \fB\ef(\fIxx\fR, or \fB\ef\fIN\fR
297: where
298: \fIx\fR and \fIxx\fR are the name of a mounted font
299: and \fIN\fR is a numerical font position.
300: It is \fInot\fR necessary to change to the Special Font;
301: characters on that font are automatically handled.
302: A request for a named but not-mounted font is \fIignored\fR.
303: \*(TR can be informed that any particular font is mounted
304: by use of the \fBfp\fR request.
305: The list of known fonts is installation dependent.
306: In the subsequent discussion of font-related requests,
307: \fIF\fR represents either a one\(sltwo-character
308: font name or the numerical font position, 1-4.
309: The current font is available (as numerical position) in the read-only number register \fB.f\fR.
310: .pg
311: \*(NR understands font control
312: and normally underlines Italic characters (see \(sc10.5).
313: .sc
314: Character size.
315: Character point sizes available are typesetter dependent, but often include
316: 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 28, and 36.
317: This is a range of 1\(sl12 inch to 1\(sl2 inch.
318: The \fBps\fR request is used to change or restore the point size.
319: Alternatively the point size may be changed between any two characters
320: by imbedding a \fB\es\fIN\fR
321: at the desired point
322: to set the size to \fIN\fR,
323: or a \fB\es\fI\(+-N\fR (1\(<=\fIN\fR\(<=9)
324: to increment\(sldecrement the size by \fIN\fR;
325: \fB\es0\fR restores the \fIprevious\fR size.
326: Requested point size values that are between two valid
327: sizes yield the larger of the two.
328: The current size is available in the \fB.s\fR register.
329: \*(NR ignores type size control.
330: .h1 *
331: .fn
332: .xx
333: *Notes are explained at the end of the Summary and Index above.
334: .ef
335: .bt
336: \fB&ps\fI|\(+-N\fR 10\|point previous E Point size
337: set to \(+-\fIN\fR.
338: Alternatively imbed \fB\es\fIN\fR or \fB\es\fI\(+-N\fR.
339: Any positive size value may be requested;
340: if invalid, the next larger valid size will result, with a
341: maximum of 36.
342: A paired sequence
343: \(pl\fIN\fR,\|\(mi\fIN\fR
344: will work because the previous requested value is also remembered.
345: Ignored in \*(NR.
346: .bt
347: \fB&fz\fI|F|\(+-N\fR off - E The characters in font \fIF\fR will be adjusted to
348: be in size \(+-\fIN\fR. Characters in the Special Font encountered during the
349: use of font \fIF\fR will have the same size modification. (Use the \fB&fz S\fR
350: request if different treatment of Special Font characters is required). \fB&fz\fR
351: must follow any \fB&fp\fR request for the position.
352: .bt
353: \fB&fz|S|\fIF|\(+-N\fR off - E The characters in the Special Font
354: will be in size \(+-\fIN\fR independent of previous \fB&fz\fR requests.
355: .bt
356: \fB&ss\fI|N\fR 12\(sl36\|em ignored E Space-character size
357: is set to \fIN\fR\(sl36\|ems.
358: This size is the minimum word spacing in adjusted text.
359: Ignored in \*(NR.
360: .bt
361: \fB&cs|\fIF\|N\|M\fR off - P Constant character space
362: (width) mode is
363: set on for font \fIF\fR (if mounted); the width of every character will be
364: taken to be \fIN\fR\(sl36 ems.
365: If \fIM\fR is absent,
366: the em is that of the character's point size;
367: if \fIM\fR is given,
368: the em is \fIM\fR-points.
369: All affected characters
370: are centered in this space, including those with an actual width
371: larger than this space.
372: Special Font characters occurring while the current font
373: is \fIF\fR are also so treated.
374: If \fIN\fR is absent, the mode is turned off.
375: The mode must be still or again in effect when the characters are physically printed.
376: Ignored in \*(NR.
377: .bt
378: \fB&bd\fI|F|N\fR off - P The characters in font \fIF\fR will be artificially
379: emboldened by printing each one twice, separated by \fIN\fR\^\(mi1 basic units.
380: A reasonable value for \fIN\fR is 3 when the character size is in the vicinity
381: of 10 points.
382: If \fIN\fR is missing the embolden mode is turned off.
383: The column heads above were printed with \fB.bd|I|3\fR.
384: The mode must be still or again in effect when the characters are physically printed.
385: Ignored in \*(NR.
386: .bt
387: \fB&bd|S|\fIF|N\fR off - P The characters in the Special Font
388: will be emboldened whenever the current font is \fIF\fR.
389: This manual was printed with \fB.bd\|S\|B\|3\fR.
390: The mode must be still or again in effect when the characters are physically printed.
391: .bt
392: \fB&ft|\fIF\fR Roman previous E Font changed to
393: \fIF\fR.
394: Alternatively, imbed \fB\ef\fIF\fR.
395: The font name \fBP\fR is reserved to mean the previous font.
396: .bt
397: \fB&fp|\fIN|F\fR R,I,B,S ignored - Font position.
398: This is a statement
399: that a font named \fIF\fR is mounted on position \fIN\fR (1-4).
400: It is a fatal error if \fIF\fR is not known.
401: The phototypesetter has four fonts physically mounted.
402: Each font consists of a film strip which can be mounted on a numbered
403: quadrant of a wheel.
404: The default mounting sequence assumed by \*(TR is
405: R, I, B, and S on positions 1, 2, 3 and 4.
406: .mh
407: Page control
408: .pg
409: Top and bottom margins are \fInot\fR automatically provided;
410: it is conventional to define two \fImacros\fR and to set \fItraps\fR
411: for them at vertical positions 0 (top) and \fI\(miN\fR (\fIN\fR from the bottom).
412: See \(sc7 and Tutorial Examples \(scT2.
413: A pseudo-page transition onto the \fIfirst\fR page occurs
414: either when the first \fIbreak\fR occurs or
415: when the first \fInon-diverted\fR text processing occurs.
416: Arrangements
417: for a trap to occur at the top of the first page
418: must be completed before this transition.
419: In the following, references to the \fIcurrent diversion\fR (\(sc7.4)
420: mean that the mechanism being described works during both
421: ordinary and diverted output (the former considered as the top diversion level).
422: .pg
423: The usable page width on the Graphic Systems phototypesetter
424: was about 7.54|inches,
425: beginning about 1\(sl27|inch from the left edge of the
426: 8|inch wide, continuous roll paper, but these characteristics are typesetter-
427: dependent.
428: The physical limitations on \*(NR output
429: are output-device dependent.
430: .h1
431: .bt
432: \fB&pl\fI|\(+-N\fR 11\|in 11\|in \fBv\fR Page length set to \fI\(+-N\fR.
433: The internal limitation is about 75|inches in \*(TR and
434: about 136|inches in \*(NR.
435: The current page length is available in the \fB.p\fR register.
436: .bt
437: \fB&bp\fI|\(+-N\fR \fIN\(eq\fR1 - B*,\fBv\fR Begin page.
438: .fn
439: .xx
440: *The use of "\ \fB\'\fR\ " as control character (instead of "\fB.\fR")
441: suppresses the break function.
442: .ef
443: The current page is ejected and a new page is begun.
444: If \fI\(+-N\fR is given, the new page number will be \fI\(+-N\fR.
445: Also see request \fBns\fR.
446: .bt
447: \fB&pn\fI|\(+-N\fR \fIN\fR\(eq1 ignored - Page number.
448: The next page (when it occurs) will have the page number \fI\(+-N\fR.
449: A \fBpn\fR must occur before the initial pseudo-page transition
450: to affect the page number of the first page.
451: The current page number is in the \fB%\fR register.
452: .bt
453: \fB&po\fI|\(+-N\fR 0;|26\(sl27\|in\(dg previous \fBv\fR Page offset.
454: .fn
455: .xx
456: \(dgValues separated by ";" are for \*(NR and \*(TR respectively.
457: .ef
458: The current \fIleft margin\fR is set to \fI\(+-N\fR.
459: The \*(TR initial value provides about 1|inch of paper margin
460: including the physical typesetter margin of 1\(sl27|inch.
461: In \*(TR the maximum (line-length)+(page-offset) is about 7.54 inches.
462: See \(sc6.
463: The current page offset is available in the \fB.o\fR register.
464: .bt
465: \fB&ne\fI|N\fR - \fIN\(eq\fR1\|\fIV\fR D,\fBv\fR Need \fIN\fR vertical space.
466: If the distance, \fID\fR, to the next trap position (see \(sc7.5) is less than \fIN\fR,
467: a forward vertical space of size \fID\fR occurs,
468: which will spring the trap.
469: If there are no remaining
470: traps on the page,
471: \fID\fR is the distance to the bottom of the page.
472: If \fID\|<\|V\fR, another line could still be output
473: and spring the trap.
474: In a diversion, \fID\fR is the distance to the \fIdiversion trap\fR, if any,
475: or is very large.
476: .bt
477: \fB&mk\fI|R\fR none internal D Mark the \fIcurrent\fR vertical place
478: in an internal register (both associated with the current diversion level),
479: or in register \fIR\fR, if given.
480: See \fBrt\fR request.
481: .bt
482: \fB&rt\fI|\(+-N\fR none internal D,\fBv\fR Return \fIupward only\fR to a marked vertical place
483: in the current diversion.
484: If \fI\(+-N\fR (w.r.t. current place) is given,
485: the place is \fI\(+-N\fR from the top of the page or diversion
486: or, if \fIN\fR is absent, to a
487: place marked by a previous \fBmk\fR.
488: Note that the \fBsp\fR request (\(sc5.3) may be used
489: in all cases instead of \fBrt\fR
490: by spacing to the absolute place stored in a explicit register;
491: e.|g. using the sequence \fB.mk|\fIR\fR ... \fB.sp|~\|\en\fIR\fBu\fR.
492: .mh
493: Text Filling, Adjusting, and Centering
494: .sc
495: Filling and adjusting.
496: Normally,
497: words are collected from input text lines
498: and assembled into a output text line
499: until some word doesn't fit.
500: An attempt is then made
501: to hyphenate the word to assemble a part
502: of it into the output line.
503: The spaces between the words on the output line
504: are then increased to spread out the line
505: to the current \fIline length\fR
506: minus any current \fIindent\fR.
507: A \fIword\fR is any string of characters delimited by
508: the \fIspace\fR character or the beginning/end of the input line.
509: Any adjacent pair of words that must be kept together
510: (neither split across output lines nor spread apart
511: in the adjustment process)
512: can be tied together by separating them with the
513: \fIunpaddable space\fR character
514: "\fB\e\ \ \fR" (backslash-space).
515: The adjusted word spacings are uniform in \*(TR
516: and the minimum interword spacing can be controlled
517: with the \fBss\fR request (\(sc2).
518: In \*(NR, they are normally nonuniform because of
519: quantization to character-size spaces;
520: however,
521: the command line option \fB\-e\fR causes uniform
522: spacing with full output device resolution.
523: Filling, adjustment, and hyphenation (\(sc13) can all be
524: prevented or controlled.
525: The \fItext length\fR on the last line output is available in the \fB.n\fR register,
526: and text base-line position on the page for this line is in the \fBnl\fR register.
527: The text base-line high-water mark (lowest place) on the current page is in
528: the \fB.h\fR register. The \fB.k\fR register (read-only) contains the horizontal size of
529: the text portion (without indent) of the current partially-collected output
530: line (if any) in the current environment.
531: .pg
532: An input text line ending with \fB.\fR\^, \fB?\fR, or \fB!\fR is taken
533: to be the end of a \fIsentence\fR, and an additional space character is
534: automatically provided during filling.
535: Multiple inter-word space characters found in the input are retained,
536: except for trailing spaces;
537: initial spaces also cause a \fIbreak\fR.
538: .pg
539: When filling is in effect, a \fB\ep\fR may be imbedded or attached to a word to
540: cause a \fIbreak\fR at the \fIend\fR of the word and have the resulting output
541: line \fIspread out\fR to fill the current line length.
542: .pg
543: .tr &&
544: A text input line that happens to begin
545: with a control character (\(sc10.4) can
546: be made to not look like a control line
547: by preceding it by
548: the non-printing, zero-width filler character \fB\e&\fR.
549: Still another way is to specify output translation of some
550: convenient character into the control character
551: using \fBtr\fR (\(sc10.5).
552: .tr &.
553: .sc
554: Interrupted text.
555: The copying of a input line in \fInofill\f (non-fill) mode can be \fIinterrupted\fR
556: by terminating
557: the partial line with a \fB\ec\fR.
558: The \fInext\fR encountered input text line will be considered to be a continuation
559: of the same line of input text.
560: Similarly,
561: a word within \fIfilled\fR text may be interrupted by terminating the
562: word (and line) with \fB\ec\fR;
563: the next encountered text will be taken as a continuation of the
564: interrupted word.
565: If the intervening control lines cause a break,
566: any partial line will be forced out along with any partial word.
567: .h1
568: .bt
569: \fB&br\fR - - B Break.
570: The filling of the line currently
571: being collected is stopped and
572: the line is output without adjustment.
573: Text lines beginning with space characters
574: and empty text lines (blank lines) also cause a break.
575: .bt
576: .lg0
577: \fB&fi\fR \(fill|on - B,E Fill subsequent output lines.
578: .lg
579: The register \fB.u\fR is 1 in fill mode and 0 in nofill mode.
580: .bt
581: \fB&nf\fR fill|on - B,E Nofill.
582: Subsequent output lines are \fIneither\fR filled \fInor\fR adjusted.
583: Input text lines are copied directly to output lines
584: \fIwithout regard\fR for the current line length.
585: .bt
586: \fB&ad\fI|c\fR adj,both adjust E \
587: Line adjustment is begun.
588: If fill mode is not on, adjustment will be deferred until
589: fill mode is back on.
590: If the type indicator \fIc\fR is present,
591: the adjustment type is changed as shown in the following table.
592: The type indicator can also be a value saved from the read-only \fB.j\fR number
593: register, which is set to contain the current adjustment mode and type.
594: .TS
595: center box;
596: c|c
597: c|l.
598: Indicator Adjust Type
599: _
600: \fBl\fR adjust left margin only
601: \fBr\fR adjust right margin only
602: \fBc\fR center
603: \fBb\fR or \fBn\fR adjust both margins
604: absent unchanged
605: .TE
606: .bt
607: \fB&na\fR adjust - E Noadjust.
608: Adjustment is turned off;
609: the right margin will be ragged.
610: The adjustment type for \fBad\fR is not changed.
611: Output line filling still occurs if fill mode is on.
612: .bt
613: \fB&ce\fI|N\fR off \fIN\fR\(eq1 B,E Center the next \fIN\fR input text lines
614: within the current (line-length minus indent).
615: If \fIN\fR\(eq\^0, any residual count is cleared.
616: A break occurs after each of the \fIN\fR input lines.
617: If the input line is too long,
618: it will be left adjusted.
619: .mh
620: Vertical Spacing
621: .sc
622: Base-line spacing.
623: The vertical spacing \fI(V)\fR between the base-lines of successive
624: output lines can be set
625: using the \fBvs\fR request
626: with a resolution of 1\(sl144\|inch\|\(eq\|1\(sl2|point
627: in \*(TR,
628: and to the output device resolution in \*(NR.
629: \fIV\fR must be large enough to accommodate the character sizes
630: on the affected output lines.
631: For the common type sizes (9-12 points),
632: usual typesetting practice is to set \fIV\fR to 2\ points greater than the
633: point size;
634: \*(TR default is 10-point type on a 12-point spacing
635: (as in this document).
636: The current \fIV\fR is available in the \fB.v\fR register.
637: Multiple-\fIV\|\fR line separation (e.\|g. double spacing) may be requested
638: with \fBls\fR.
639: .sc
640: Extra line-space.
641: If a word contains a vertically tall construct requiring
642: the output line containing it to have extra vertical space
643: before and\(slor after it,
644: the \fIextra-line-space\fR function \fB\ex\fI\'N\|\|\'\fR
645: can be imbedded in or attached to that word.
646: In this and other functions having a pair of delimiters around
647: their parameter (here \fB\'\fR\|),
648: the delimiter choice is arbitrary,
649: except that it can't look like the continuation of a number expression for \fIN\fR.
650: If \fIN\fR is negative,
651: the output line containing the word will
652: be preceded by \fIN\fR extra vertical space;
653: if \fIN\fR is positive,
654: the output line containing the word
655: will be followed by \fIN\fR extra vertical space.
656: If successive requests for extra space apply to the same line,
657: the maximum values are used.
658: The most recently utilized post-line extra line-space is available in the \fB.a\fR register.
659: .sc
660: Blocks of vertical space.
661: A block of vertical space is ordinarily requested using \fBsp\fR,
662: which honors the \fIno-space\fR mode and which does
663: not space \fIpast\fR a trap.
664: A contiguous block of vertical space may be reserved using \fBsv\fR.
665: .h1
666: .bt
667: \fB&vs\fI|N\fR 1\(sl6in;12pts previous E,\fBp\fR Set vertical base-line spacing size \fIV\fR.
668: Transient \fIextra\fR vertical space available with \fB\ex\fI\'N\|\|\'\fR (see above).
669: .bt
670: \fB&ls\fI|N\fR \fIN\(eq\^\fR1 previous E \fILine\fR spacing
671: set to \fI\(+-N\fR.
672: \fIN\(mi\fR1 \fIV\fR\^s \fI(blank lines)\fR are
673: appended to each output text line. The (read-only) number register \fB.L\fR
674: is set to contain the current line-spacing value.
675: Appended blank lines are omitted, if the text or previous appended blank line reached a trap position.
676: .bt
677: \fB&sp\fI|N\fR - \fIN\fR\(eq1\fIV\fR B,\fBv\fR Space vertically in \fIeither\fR direction.
678: If \fIN\fR is negative, the motion is \fIbackward\fR (upward)
679: and is limited to the distance to the top of the page.
680: Forward (downward) motion is truncated to the distance to the
681: nearest trap.
682: If the no-space mode is on,
683: no spacing occurs (see \fBns\fR, and \fBrs\fR below).
684: .bt
685: \fB&sv\fI|N\fR - \fIN\(eq\fR1\fIV\fR \fBv\fR Save a contiguous vertical block of size \fIN\fR.
686: If the distance to the next trap is greater
687: than \fIN\fR, \fIN\fR vertical space is output.
688: No-space mode has \fIno\fR effect.
689: If this distance is less than \fIN\fR,
690: no vertical space is immediately output,
691: but \fIN\fR is remembered for later output (see \fBos\fR).
692: Subsequent \fBsv\fR requests will overwrite any still remembered \fIN\fR.
693: .bt
694: \fB&os\fR - - - Output saved vertical space.
695: No-space mode has \fIno\fR effect.
696: Used to finally output a block of vertical space requested
697: by an earlier \fBsv\fR request.
698: .bt
699: \fB&ns\fR space - D No-space mode turned on.
700: When on, the no-space mode inhibits \fBsp\fR requests and
701: \fBbp\fR requests \fIwithout\fR a next page number.
702: The no-space mode is turned off when a line of
703: output occurs, or with \fBrs\fR.
704: .bt
705: \fB&rs\fR space - D Restore spacing.
706: The no-space mode is turned off.
707: .bt
708: Blank|text|line. - B Causes a break and
709: outputs a blank line just like \fBsp|1\fR.
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