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diff --git a/share/doc/usd/21.troff/m1 b/share/doc/usd/21.troff/m1 new file mode 100644 index 000000000000..0df1d52ac56c --- /dev/null +++ b/share/doc/usd/21.troff/m1 @@ -0,0 +1,746 @@ +.\" Copyright (C) Caldera International Inc. 2001-2002. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions are +.\" met: +.\" +.\" Redistributions of source code and documentation must retain the above +.\" copyright notice, this list of conditions and the following +.\" disclaimer. +.\" +.\" Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" +.\" This product includes software developed or owned by Caldera +.\" International, Inc. Neither the name of Caldera International, Inc. +.\" nor the names of other contributors may be used to endorse or promote +.\" products derived from this software without specific prior written +.\" permission. +.\" +.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA +.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +.\" DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE +.\" FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR +.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, +.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE +.\" OR OTHERWISE) RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN +.\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" @(#)m1 8.1 (Berkeley) 8/14/93 +.\" +.\" $FreeBSD$ +.nr p 0 1 +.tr | +.tr ~| +.rm mx +.br +.ce +.ft B +.ps +2 +.rs +.\".sp1.0i +REFERENCE MANUAL +.ft R +.ps -2 +.sp +.mh +General Explanation +.sc +Form of input. +Input consists of \fItext lines\fR, which are destined to be printed, +interspersed with \fIcontrol lines\fR, +which set parameters or otherwise control subsequent processing. +Control lines begin with a \fIcontrol character\fR\(em\ +normally \fB.\fR (period) or \fB\'\fR (acute accent)\(em\ +followed by a one or two character name that specifies +a basic \fIrequest\fR or the substitution of +a user-defined \fImacro\fR in place of the control line. +The control character \fB\'\fR suppresses the \fIbreak\fR function\(em\ +the forced output of a partially filled line\(em\ +caused by certain requests. +The control character may be separated from the request/macro name by +white space (spaces and/or tabs) for \(aesthetic reasons. +Names must be followed by either +space or newline. +Control lines with unrecognized names are ignored. +.pg +Various special functions may be introduced anywhere in the input by +means of an \fIescape\fR character, normally \fB\e\fR. +For example, the function +\fB\en\fIR\fR +causes the interpolation (insertion in place) of the contents of the +\fInumber register R\fR +in place of the function; +here \fIR\fR is either a single character name +as in \fB\en\fIx\fR, +or left-parenthesis-introduced, two-character name as in \fB\en(\fIxx\fR. +.sc +Formatter and device resolution. +\*(TR internally uses 432 units\(slinch, (for historical reasons, corresponding to +the Graphic Systems phototypesetter +which had a horizontal resolution of +1\(sl432 inch and a vertical resolution +of 1\(sl144 inch.) +\*(NR internally uses 240 units\(slinch, +corresponding to the least common multiple of the +horizontal and vertical resolutions of various +typewriter-like output devices. +\*(TR rounds horizontal\(slvertical numerical parameter input to its own +internal horizontal\(slvertical resolution. +\*(NR similarly rounds numerical input to the actual resolution +of the output device indicated by the \fB\(miT\fR option +(default Model 37 Teletype). +.sc +Numerical parameter input. +Both \*(NR and \*(TR +accept numerical input with the scale +indicator suffixes +shown in the following table, +where +\fIS\fR is the current type size in points, +\fIV\fR is the current vertical line spacing in +basic units, +and +\fIC\fR is a \fInominal character width\fR in basic units. +.TS +center box; +c|c|ls +c|c|ll +c|l|l|l. +Scale Number of basic units +Indicator Meaning \*(TR \*(NR +_ +\fBi\fR Inch 432 240 +\fBc\fR Centimeter 432\(mu50\(sl127 240\(mu50\(sl127 +\fBP\fR Pica = 1\(sl6 inch 72 240\(sl6 +\fBm\fR Em = \fIS\fR points 6\(mu\fIS\fR \fIC\fR +\fBn\fR En = Em\(sl2 3\(mu\fIS\fR \fIC, same as Em\fR +\fBp\fR Point = 1\(sl72 inch 6 240\(sl72 +\fBu\fR Basic unit 1 1 +\fBv\fR Vertical line space \fIV\fR \fIV\fR +none Default, see below +.TE +In \*(NR, \fIboth\fR the em and the en are taken to be equal to the \fIC\fR, +which is output-device dependent; +common values are 1\(sl10 and 1\(sl12 inch. +Actual character widths in \*(NR need not be all the same and constructed characters +such as \(mi> (\(->) are often extra wide. +The default scaling is ems for the horizontally-oriented requests +and functions +\fBll\fR, +\fBin\fR, +\fBti\fR, +\fBta\fR, +\fBlt\fR, +\fBpo\fR, +\fBmc\fR, +\fB\eh\fR, +and +\fB\el\fR; +\fIV\^\fRs +for the vertically-oriented requests and functions +\fBpl\fR, +\fBwh\fR, +\fBch\fR, +\fBdt\fR, +\fBsp\fR, +\fBsv\fR, +\fBne\fR, +\fBrt\fR, +\fB\ev\fR, +\fB\ex\fR, +and +\fB\eL\fR; +\fBp\fR for the \fBvs\fR request; +and \fBu\fR for the requests +\fBnr\fR, +\fBif\fR, +and +\fBie\fR. +\fIAll\fR other requests ignore any scale indicators. +When a number register containing an already appropriately scaled number +is interpolated to provide numerical input, +the unit scale indicator +\fBu\fR may need to be appended to prevent +an additional inappropriate default scaling. +The number, \fIN\fR, may be specified in decimal-fraction form +but the parameter finally stored is rounded to an integer number of basic units. +.pg +The \fIabsolute position\fR indicator \fB~\fR may be prefixed +to a number \fIN\fR +to generate the distance to the vertical or horizontal place \fIN\fR. +For vertically-oriented requests and functions, \fB~\|\fIN\fR +becomes the distance in basic units from the current vertical place on the page or in a \fIdiversion\fR (\(sc7.4) +to the vertical place \fIN\fR. +For \fIall\fR other requests and functions, +\fB~\|\fIN\fR +becomes the distance from +the current horizontal place on the \fIinput\fR line to the horizontal place \fIN\fR. +For example, +.x1 +\&\fB.sp ~\|3.2c\fR +.x2 +will space \fIin the required direction\fR to 3.2 centimeters from the top of the page. +.sc +.tr && +Numerical expressions. +Wherever numerical input is expected, an expression involving parentheses, +the arithmetic operators \fB\(pl\fR, \fB\(mi\fR, \fB\(sl\fR, \fB\(**\fR, \fB%\fR (mod), +and the logical operators +\fB<\fR, +\fB>\fR, +\fB<\(eq\fR, +\fB>\(eq\fR, +\fB\(eq\fR (or \fB\(eq\(eq\fR), +\fB&\fR\ (and), +\fB:\fR\ (or) +may be used. +Except where controlled by parentheses, evaluation of expressions is left-to-right; +there is no operator precedence. +In the case of certain requests, an initial \fB\(pl\fR or \fB\(mi\fR is stripped +and interpreted as an increment or decrement indicator respectively. +In the presence of default scaling, the desired scale indicator must be +attached to \fIevery\fR number in an expression +for which the desired and default scaling differ. +For example, +if the number register \fBx\fR contains 2 +and the current point size is 10, +then +.br +.tr &. +.x1 +.ft B +\&.ll (4.25i\(pl\enxP\(pl3)\(sl2u +.ft R +.x2 +will set the line length to 1\(sl2 the sum of 4.25 inches \(pl 2 picas \(pl 30 points. +.sc +Notation. +Numerical parameters are indicated in this manual in two ways. +\(+-\fIN\fR means that the argument may take the forms \fIN\fR, \(pl\fIN\fR, or \(mi\fIN\fR and +that the corresponding effect is to set the affected parameter +to \fIN\fR, to increment it by \fIN\fR, or to decrement it by \fIN\fR respectively. +Plain \fIN\fR means that an initial algebraic sign is \fInot\fR +an increment indicator, +but merely the sign of \fIN\fR. +Generally, unreasonable numerical input is either ignored +or truncated to a reasonable value. +For example, +most requests expect to set parameters to non-negative +values; +exceptions are +\fBsp\fR, +\fBwh\fR, +\fBch\fR, +\fBnr\fR, +and +\fBif\fR. +The requests +\fBps\fR, +\fBft\fR, +\fBpo\fR, +\fBvs\fR, +\fBls\fR, +\fBll\fR, +\fBin\fR, +and +\fBlt\fR +restore the \fIprevious\fR parameter value in the \fIabsence\fR +of an argument. +.pg +Single character arguments are indicated by single lower case letters +and +one/two character arguments are indicated by a pair of lower case letters. +Character string arguments are indicated by multi-character mnemonics. +.mh +Font and Character Size Control +.sc +Character set. +The \*(TR character set consists of a typesetter-dependent basic +character set plus a Special Mathematical Font character +set\(emeach having 102 characters. +An example of these character sets is shown in the Appendix Table|I. +All printable \s-1ASCII\s+1 characters are included, +with some on the Special Font. +With three exceptions, these \s-1ASCII\s+1 characters are input as themselves, +and non-\s-1ASCII\s+1 characters are input in the form \fB\e(\fIxx\fR where +\fIxx\fR is a two-character name given in the Appendix Table|II. +The three \s-1ASCII\s+1 exceptions are mapped as follows: +.TS +center box; +cs|cs +cc|cc +cl|cl. +\s-1ASCII\s+1 Input Printed by \*(TR +Character Name Character Name +_ +\' acute accent ' close quote +\` grave accent ` open quote +\(mi minus - hyphen +.TE +.tr ~~ +The characters +\fB\'\fR, +\fB\`\fR, +and +\fB\-\fR +may be input +by \fB\e\'\fR, \fB\e\`\fR, and \fB\e\-\fR respectively or by their names (Table II). +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 +only on the Special Font and are printed as a 1-em space if that font +is not mounted. +.pg +.tr ~| +\*(NR understands the entire \*(TR character set, +but can in general print only \s-1ASCII\s+1 +characters, +additional characters as may be available on +the output device, +such characters as may be able to be constructed +by overstriking or other combination, +and those that can reasonably be mapped +into other printable characters. +The exact behavior is determined by a driving +table prepared for each device. +The characters +\fB\'\fR, +\fB\`\fR, +and +\fB\(ul\fR +print +as themselves. +.sc +Fonts. +The default mounted fonts are +Times Roman (\fBR\fR), +Times Italic (\fBI\fR), +Times Bold (\fBB\fR), +and the Special Mathematical Font (\fBS\fR) +on physical typesetter positions 1, 2, 3, and 4 respectively. +These fonts are used in this document. +The \fIcurrent\fR font, initially Roman, may be changed +(among the mounted fonts) +by use of the \fBft\fR request, +or by imbedding at any desired point +either \fB\ef\fIx\fR, \fB\ef(\fIxx\fR, or \fB\ef\fIN\fR +where +\fIx\fR and \fIxx\fR are the name of a mounted font +and \fIN\fR is a numerical font position. +It is \fInot\fR necessary to change to the Special Font; +characters on that font are automatically handled. +A request for a named but not-mounted font is \fIignored\fR. +\*(TR can be informed that any particular font is mounted +by use of the \fBfp\fR request. +The list of known fonts is installation dependent. +In the subsequent discussion of font-related requests, +\fIF\fR represents either a one\(sltwo-character +font name or the numerical font position, 1-4. +The current font is available (as numerical position) in the read-only number register \fB.f\fR. +.pg +\*(NR understands font control +and normally underlines Italic characters (see \(sc10.5). +.sc +Character size. +Character point sizes available are typesetter dependent, but often include +6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 28, and 36. +This is a range of 1\(sl12 inch to 1\(sl2 inch. +The \fBps\fR request is used to change or restore the point size. +Alternatively the point size may be changed between any two characters +by imbedding a \fB\es\fIN\fR +at the desired point +to set the size to \fIN\fR, +or a \fB\es\fI\(+-N\fR (1\(<=\fIN\fR\(<=9) +to increment\(sldecrement the size by \fIN\fR; +\fB\es0\fR restores the \fIprevious\fR size. +Requested point size values that are between two valid +sizes yield the larger of the two. +The current size is available in the \fB.s\fR register. +\*(NR ignores type size control. +.h1 * +.fn +.xx +*Notes are explained at the end of the Summary and Index above. +.ef +.bt +\fB&ps\fI|\(+-N\fR 10\|point previous E Point size +set to \(+-\fIN\fR. +Alternatively imbed \fB\es\fIN\fR or \fB\es\fI\(+-N\fR. +Any positive size value may be requested; +if invalid, the next larger valid size will result, with a +maximum of 36. +A paired sequence +\(pl\fIN\fR,\|\(mi\fIN\fR +will work because the previous requested value is also remembered. +Ignored in \*(NR. +.bt +\fB&fz\fI|F|\(+-N\fR off - E The characters in font \fIF\fR will be adjusted to +be in size \(+-\fIN\fR. Characters in the Special Font encountered during the +use of font \fIF\fR will have the same size modification. (Use the \fB&fz S\fR +request if different treatment of Special Font characters is required). \fB&fz\fR +must follow any \fB&fp\fR request for the position. +.bt +\fB&fz|S|\fIF|\(+-N\fR off - E The characters in the Special Font +will be in size \(+-\fIN\fR independent of previous \fB&fz\fR requests. +.bt +\fB&ss\fI|N\fR 12\(sl36\|em ignored E Space-character size +is set to \fIN\fR\(sl36\|ems. +This size is the minimum word spacing in adjusted text. +Ignored in \*(NR. +.bt +\fB&cs|\fIF\|N\|M\fR off - P Constant character space +(width) mode is +set on for font \fIF\fR (if mounted); the width of every character will be +taken to be \fIN\fR\(sl36 ems. +If \fIM\fR is absent, +the em is that of the character's point size; +if \fIM\fR is given, +the em is \fIM\fR-points. +All affected characters +are centered in this space, including those with an actual width +larger than this space. +Special Font characters occurring while the current font +is \fIF\fR are also so treated. +If \fIN\fR is absent, the mode is turned off. +The mode must be still or again in effect when the characters are physically printed. +Ignored in \*(NR. +.bt +\fB&bd\fI|F|N\fR off - P The characters in font \fIF\fR will be artificially +emboldened by printing each one twice, separated by \fIN\fR\^\(mi1 basic units. +A reasonable value for \fIN\fR is 3 when the character size is in the vicinity +of 10 points. +If \fIN\fR is missing the embolden mode is turned off. +The column heads above were printed with \fB.bd|I|3\fR. +The mode must be still or again in effect when the characters are physically printed. +Ignored in \*(NR. +.bt +\fB&bd|S|\fIF|N\fR off - P The characters in the Special Font +will be emboldened whenever the current font is \fIF\fR. +This manual was printed with \fB.bd\|S\|B\|3\fR. +The mode must be still or again in effect when the characters are physically printed. +.bt +\fB&ft|\fIF\fR Roman previous E Font changed to +\fIF\fR. +Alternatively, imbed \fB\ef\fIF\fR. +The font name \fBP\fR is reserved to mean the previous font. +.bt +\fB&fp|\fIN|F\fR R,I,B,S ignored - Font position. +This is a statement +that a font named \fIF\fR is mounted on position \fIN\fR (1-4). +It is a fatal error if \fIF\fR is not known. +The phototypesetter has four fonts physically mounted. +Each font consists of a film strip which can be mounted on a numbered +quadrant of a wheel. +The default mounting sequence assumed by \*(TR is +R, I, B, and S on positions 1, 2, 3 and 4. +.mh +Page control +.pg +Top and bottom margins are \fInot\fR automatically provided; +it is conventional to define two \fImacros\fR and to set \fItraps\fR +for them at vertical positions 0 (top) and \fI\(miN\fR (\fIN\fR from the bottom). +See \(sc7 and Tutorial Examples \(scT2. +A pseudo-page transition onto the \fIfirst\fR page occurs +either when the first \fIbreak\fR occurs or +when the first \fInon-diverted\fR text processing occurs. +Arrangements +for a trap to occur at the top of the first page +must be completed before this transition. +In the following, references to the \fIcurrent diversion\fR (\(sc7.4) +mean that the mechanism being described works during both +ordinary and diverted output (the former considered as the top diversion level). +.pg +The usable page width on the Graphic Systems phototypesetter +was about 7.54|inches, +beginning about 1\(sl27|inch from the left edge of the +8|inch wide, continuous roll paper, but these characteristics are typesetter- +dependent. +The physical limitations on \*(NR output +are output-device dependent. +.h1 +.bt +\fB&pl\fI|\(+-N\fR 11\|in 11\|in \fBv\fR Page length set to \fI\(+-N\fR. +The internal limitation is about 75|inches in \*(TR and +about 136|inches in \*(NR. +The current page length is available in the \fB.p\fR register. +.bt +\fB&bp\fI|\(+-N\fR \fIN\(eq\fR1 - B*,\fBv\fR Begin page. +.fn +.xx +*The use of "\ \fB\'\fR\ " as control character (instead of "\fB.\fR") +suppresses the break function. +.ef +The current page is ejected and a new page is begun. +If \fI\(+-N\fR is given, the new page number will be \fI\(+-N\fR. +Also see request \fBns\fR. +.bt +\fB&pn\fI|\(+-N\fR \fIN\fR\(eq1 ignored - Page number. +The next page (when it occurs) will have the page number \fI\(+-N\fR. +A \fBpn\fR must occur before the initial pseudo-page transition +to affect the page number of the first page. +The current page number is in the \fB%\fR register. +.bt +\fB&po\fI|\(+-N\fR 0;|26\(sl27\|in\(dg previous \fBv\fR Page offset. +.fn +.xx +\(dgValues separated by ";" are for \*(NR and \*(TR respectively. +.ef +The current \fIleft margin\fR is set to \fI\(+-N\fR. +The \*(TR initial value provides about 1|inch of paper margin +including the physical typesetter margin of 1\(sl27|inch. +In \*(TR the maximum (line-length)+(page-offset) is about 7.54 inches. +See \(sc6. +The current page offset is available in the \fB.o\fR register. +.bt +\fB&ne\fI|N\fR - \fIN\(eq\fR1\|\fIV\fR D,\fBv\fR Need \fIN\fR vertical space. +If the distance, \fID\fR, to the next trap position (see \(sc7.5) is less than \fIN\fR, +a forward vertical space of size \fID\fR occurs, +which will spring the trap. +If there are no remaining +traps on the page, +\fID\fR is the distance to the bottom of the page. +If \fID\|<\|V\fR, another line could still be output +and spring the trap. +In a diversion, \fID\fR is the distance to the \fIdiversion trap\fR, if any, +or is very large. +.bt +\fB&mk\fI|R\fR none internal D Mark the \fIcurrent\fR vertical place +in an internal register (both associated with the current diversion level), +or in register \fIR\fR, if given. +See \fBrt\fR request. +.bt +\fB&rt\fI|\(+-N\fR none internal D,\fBv\fR Return \fIupward only\fR to a marked vertical place +in the current diversion. +If \fI\(+-N\fR (w.r.t. current place) is given, +the place is \fI\(+-N\fR from the top of the page or diversion +or, if \fIN\fR is absent, to a +place marked by a previous \fBmk\fR. +Note that the \fBsp\fR request (\(sc5.3) may be used +in all cases instead of \fBrt\fR +by spacing to the absolute place stored in an explicit register; +e.|g. using the sequence \fB.mk|\fIR\fR ... \fB.sp|~\|\en\fIR\fBu\fR. +.mh +Text Filling, Adjusting, and Centering +.sc +Filling and adjusting. +Normally, +words are collected from input text lines +and assembled into an output text line +until some word doesn't fit. +An attempt is then made +to hyphenate the word to assemble a part +of it into the output line. +The spaces between the words on the output line +are then increased to spread out the line +to the current \fIline length\fR +minus any current \fIindent\fR. +A \fIword\fR is any string of characters delimited by +the \fIspace\fR character or the beginning/end of the input line. +Any adjacent pair of words that must be kept together +(neither split across output lines nor spread apart +in the adjustment process) +can be tied together by separating them with the +\fIunpaddable space\fR character +"\fB\e\ \ \fR" (backslash-space). +The adjusted word spacings are uniform in \*(TR +and the minimum interword spacing can be controlled +with the \fBss\fR request (\(sc2). +In \*(NR, they are normally nonuniform because of +quantization to character-size spaces; +however, +the command line option \fB\-e\fR causes uniform +spacing with full output device resolution. +Filling, adjustment, and hyphenation (\(sc13) can all be +prevented or controlled. +The \fItext length\fR on the last line output is available in the \fB.n\fR register, +and text base-line position on the page for this line is in the \fBnl\fR register. +The text base-line high-water mark (lowest place) on the current page is in +the \fB.h\fR register. The \fB.k\fR register (read-only) contains the horizontal size of +the text portion (without indent) of the current partially-collected output +line (if any) in the current environment. +.pg +An input text line ending with \fB.\fR\^, \fB?\fR, or \fB!\fR is taken +to be the end of a \fIsentence\fR, and an additional space character is +automatically provided during filling. +Multiple inter-word space characters found in the input are retained, +except for trailing spaces; +initial spaces also cause a \fIbreak\fR. +.pg +When filling is in effect, a \fB\ep\fR may be imbedded or attached to a word to +cause a \fIbreak\fR at the \fIend\fR of the word and have the resulting output +line \fIspread out\fR to fill the current line length. +.pg +.tr && +A text input line that happens to begin +with a control character (\(sc10.4) can +be made to not look like a control line +by preceding it by +the non-printing, zero-width filler character \fB\e&\fR. +Still another way is to specify output translation of some +convenient character into the control character +using \fBtr\fR (\(sc10.5). +.tr &. +.sc +Interrupted text. +The copying of an input line in \fInofill\fR +(non-fill) mode can be \fIinterrupted\fR by terminating +the partial line with a \fB\ec\fR. +The \fInext\fR encountered input text line will be considered to be a continuation +of the same line of input text. +Similarly, +a word within \fIfilled\fR text may be interrupted by terminating the +word (and line) with \fB\ec\fR; +the next encountered text will be taken as a continuation of the +interrupted word. +If the intervening control lines cause a break, +any partial line will be forced out along with any partial word. +.h1 +.bt +\fB&br\fR - - B Break. +The filling of the line currently +being collected is stopped and +the line is output without adjustment. +Text lines beginning with space characters +and empty text lines (blank lines) also cause a break. +.bt +.lg 0 +\fB&fi\fR \(fill|on - B,E Fill subsequent output lines. +.lg +The register \fB.u\fR is 1 in fill mode and 0 in nofill mode. +.bt +\fB&nf\fR fill|on - B,E Nofill. +Subsequent output lines are \fIneither\fR filled \fInor\fR adjusted. +Input text lines are copied directly to output lines +\fIwithout regard\fR for the current line length. +.bt +\fB&ad\fI|c\fR adj,both adjust E \ +Line adjustment is begun. +If fill mode is not on, adjustment will be deferred until +fill mode is back on. +If the type indicator \fIc\fR is present, +the adjustment type is changed as shown in the following table. +The type indicator can also be a value saved from the read-only \fB.j\fR number +register, which is set to contain the current adjustment mode and type. +.TS +center box; +c|c +c|l. +Indicator Adjust Type +_ +\fBl\fR adjust left margin only +\fBr\fR adjust right margin only +\fBc\fR center +\fBb\fR or \fBn\fR adjust both margins +absent unchanged +.TE +.bt +\fB&na\fR adjust - E Noadjust. +Adjustment is turned off; +the right margin will be ragged. +The adjustment type for \fBad\fR is not changed. +Output line filling still occurs if fill mode is on. +.bt +\fB&ce\fI|N\fR off \fIN\fR\(eq1 B,E Center the next \fIN\fR input text lines +within the current (line-length minus indent). +If \fIN\fR\(eq\^0, any residual count is cleared. +A break occurs after each of the \fIN\fR input lines. +If the input line is too long, +it will be left adjusted. +.mh +Vertical Spacing +.sc +Base-line spacing. +The vertical spacing \fI(V)\fR between the base-lines of successive +output lines can be set +using the \fBvs\fR request +with a resolution of 1\(sl144\|inch\|\(eq\|1\(sl2|point +in \*(TR, +and to the output device resolution in \*(NR. +\fIV\fR must be large enough to accommodate the character sizes +on the affected output lines. +For the common type sizes (9-12 points), +usual typesetting practice is to set \fIV\fR to 2\ points greater than the +point size; +\*(TR default is 10-point type on a 12-point spacing +(as in this document). +The current \fIV\fR is available in the \fB.v\fR register. +Multiple-\fIV\|\fR line separation (e.\|g. double spacing) may be requested +with \fBls\fR. +.sc +Extra line-space. +If a word contains a vertically tall construct requiring +the output line containing it to have extra vertical space +before and\(slor after it, +the \fIextra-line-space\fR function \fB\ex\fI\'N\|\|\'\fR +can be imbedded in or attached to that word. +In this and other functions having a pair of delimiters around +their parameter (here \fB\'\fR\|), +the delimiter choice is arbitrary, +except that it can't look like the continuation of a number expression for \fIN\fR. +If \fIN\fR is negative, +the output line containing the word will +be preceded by \fIN\fR extra vertical space; +if \fIN\fR is positive, +the output line containing the word +will be followed by \fIN\fR extra vertical space. +If successive requests for extra space apply to the same line, +the maximum values are used. +The most recently utilized post-line extra line-space is available in the \fB.a\fR register. +.sc +Blocks of vertical space. +A block of vertical space is ordinarily requested using \fBsp\fR, +which honors the \fIno-space\fR mode and which does +not space \fIpast\fR a trap. +A contiguous block of vertical space may be reserved using \fBsv\fR. +.h1 +.bt +\fB&vs\fI|N\fR 1\(sl6in;12pts previous E,\fBp\fR Set vertical base-line spacing size \fIV\fR. +Transient \fIextra\fR vertical space available with \fB\ex\fI\'N\|\|\'\fR (see above). +.bt +\fB&ls\fI|N\fR \fIN\(eq\^\fR1 previous E \fILine\fR spacing +set to \fI\(+-N\fR. +\fIN\(mi\fR1 \fIV\fR\^s \fI(blank lines)\fR are +appended to each output text line. The (read-only) number register \fB.L\fR +is set to contain the current line-spacing value. +Appended blank lines are omitted, if the text or previous appended blank line reached a trap position. +.bt +\fB&sp\fI|N\fR - \fIN\fR\(eq1\fIV\fR B,\fBv\fR Space vertically in \fIeither\fR direction. +If \fIN\fR is negative, the motion is \fIbackward\fR (upward) +and is limited to the distance to the top of the page. +Forward (downward) motion is truncated to the distance to the +nearest trap. +If the no-space mode is on, +no spacing occurs (see \fBns\fR, and \fBrs\fR below). +.bt +\fB&sv\fI|N\fR - \fIN\(eq\fR1\fIV\fR \fBv\fR Save a contiguous vertical block of size \fIN\fR. +If the distance to the next trap is greater +than \fIN\fR, \fIN\fR vertical space is output. +No-space mode has \fIno\fR effect. +If this distance is less than \fIN\fR, +no vertical space is immediately output, +but \fIN\fR is remembered for later output (see \fBos\fR). +Subsequent \fBsv\fR requests will overwrite any still remembered \fIN\fR. +.bt +\fB&os\fR - - - Output saved vertical space. +No-space mode has \fIno\fR effect. +Used to finally output a block of vertical space requested +by an earlier \fBsv\fR request. +.bt +\fB&ns\fR space - D No-space mode turned on. +When on, the no-space mode inhibits \fBsp\fR requests and +\fBbp\fR requests \fIwithout\fR a next page number. +The no-space mode is turned off when a line of +output occurs, or with \fBrs\fR. +.bt +\fB&rs\fR space - D Restore spacing. +The no-space mode is turned off. +.bt +Blank|text|line. - B Causes a break and +outputs a blank line just like \fBsp|1\fR. |