/share/doc/usd/22.trofftut/tt04

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  5.\"	@(#)tt04	8.1 (Berkeley) 6/8/93
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 42.\" $FreeBSD$
 43.\"
 44.NH
 45Indents and Line Lengths
 46.PP
 47.UL troff
 48starts with a line length of 6.5 inches,
 49which some people think is too wide for 8\(12\(mu11 paper.
 50To reset the line length,
 51use
 52the
 53.BD .ll
 54command, as in
 55.P1
 56^ll 6i
 57.P2
 58As with
 59.BD .sp ,
 60the actual length can be specified in several ways;
 61inches are probably the most intuitive.
 62.PP
 63The maximum line length provided by the typesetter is 7.5 inches, by the way.
 64To use the full width, you will have to reset the default physical left margin (``page offset''),
 65which is normally slightly less than one inch from the left edge
 66of the paper.
 67This is done by the
 68.BD .po
 69command.
 70.P1
 71^po 0
 72.P2
 73sets the offset as far to the left as it will go.
 74.WS
 75.PP
 76The indent command
 77.BD .in
 78causes the left margin to be indented
 79by some specified amount from the page offset.
 80If we use
 81.BD .in
 82to move the left margin in,
 83and
 84.BD .ll
 85to move the right margin to the left,
 86we can
 87make offset blocks of text:
 88.P1
 89^in 0.3i
 90^ll \(mi0.3i
 91text to be set into a block
 92^ll +0.3i
 93^in \(mi0.3i
 94.P2
 95will create a block that looks like this:
 96.P1
 97.fi
 98.ll -0.3i
 99Pater noster qui est in caelis sanctificetur nomen tuum;
100adveniat regnum tuum; fiat voluntas tua, sicut in caelo,
101et in terra. ...
102Amen.
103.ll +0.3i
104.P2
105Notice the use of `+' and `\(mi'
106to specify the amount of change.
107These change the previous setting by the specified amount,
108rather than just overriding it.
109The distinction is quite important:
110.BD .ll\ +1i
111makes lines one inch longer;
112.BD .ll\ 1i
113makes them one inch
114.ul
115long.
116.PP
117With
118.BD .in ,
119.BD .ll
120and
121.BD .po ,
122the previous value is used if no argument is specified.
123.PP
124To indent a single line, use the `temporary indent'
125command
126.BD .ti .
127For example, all paragraphs in this memo
128effectively begin with the command
129.P1
130^ti 3
131.P2
132Three of what?
133The default unit for
134.BD .ti ,
135as for most horizontally oriented commands
136.BD .ll , (
137.BD .in ,
138.BD .po ),
139is ems;
140an em is roughly the width of the letter `m'
141in the current point size.
142(Precisely, an em in size
143.ul
144p
145is
146.ul
147p
148points.)
149Although inches are usually clearer than ems to people who don't set type
150for a living,
151ems have a place:
152they are a measure of size that is proportional to the current point size.
153If you want to make text that keeps its proportions
154regardless of point size,
155you should use ems for all dimensions.
156Ems can be specified as scale factors directly,
157as in
158.BD .ti\ 2.5m .
159.PP
160Lines can also be indented negatively
161if the indent is already positive:
162.P1
163^ti \(mi0.3i
164.P2
165causes the next line to be moved back three tenths of an inch.
166Thus to make a decorative initial capital,
167we indent the whole paragraph, then move the letter `P' back with
168a
169.BD .ti
170command:
171.P1
172.ll -0.3i
173.fi
174.in +.3i
175.ti -0.3i
176\s36\v'2'P\v'-2'\s0ater noster qui est in caelis sanctificetur
177nomen tuum;
178adveniat regnum tuum;
179'in -.3i
180fiat voluntas tua,
181sicut in caelo, et in terra. ...
182Amen.
183.ll +0.3i
184.P2
185Of course, there is also some trickery to make the `P'
186bigger (just a `\es36P\es0'),
187and to move it
188down from its normal position
189(see the section on local motions).