Plan 9 from Bell Labs’s /usr/web/sources/contrib/steve/root/sys/lib/texmf/doc/generic/xypic/xyguide-html/node33.html

Copyright © 2021 Plan 9 Foundation.
Distributed under the MIT License.
Download the Plan 9 distribution.


<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 3.0//EN">
<!--Converted with LaTeX2HTML 96.1-h (September 30, 1996) by Nikos Drakos ([email protected]), CBLU, University of Leeds -->
<HTML>
<HEAD>
<TITLE>A Answers to all exercises</TITLE>
<META NAME="description" CONTENT="A Answers to all exercises">
<META NAME="keywords" CONTENT="xyguide-html">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">
<LINK REL=STYLESHEET HREF="xyguide-html.css">
</HEAD>
<BODY LANG="EN" BGCOLOR="#FFFFFF">
 <P ALIGN=RIGHT><FONT SIZE=1>Xy-pic User's Guide</FONT> <A HREF="18pt.html"><IMG SRC="./quest.gif" ALIGN=TOP HEIGHT=27 WIDTH=21 BORDER=0 ALT="?"></A><A NAME="tex2html463" HREF="node32.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="previous" SRC="./previous.gif"></A><A NAME="tex2html467" HREF="node28.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="previous" SRC="./previoussection.gif"></A><A NAME="tex2html469" HREF="xyguide-html.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="up" SRC="./up.gif"></A><A NAME="tex2html465" HREF="node34.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="next" SRC="./nextsection.gif"></A><A NAME="tex2html471" HREF="node34.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="next" SRC="./next.gif"></A></P><H1><A NAME="SECTION00070000000000000000">A Answers to all exercises</A></H1><A NAME="Answer1">&#160;</A><H4><A NAME="SECTION00070010000000000000">Answer to exercise 1.</A></H4>
<P>
<A HREF="node6.html#Exercise1">Question.</A>
<P>
The target <code>[]</code> is the current entry itself.
<P>
<A NAME="Answer2">&#160;</A><H4><A NAME="SECTION00070020000000000000">Answer to exercise 2.</A></H4><A HREF="node6.html#Exercise2">Question.</A>
<P>
The author did 
<BLOCKQUOTE><PRE>\xymatrix{
 {\bullet} \ar@{--}[d]\ar@{=}[dr]\ar@{-}[r]
           &amp; {\bullet} \ar@{.}[d] \\
 {\bullet} &amp; {\bullet} \ar[l] }</PRE></BLOCKQUOTE>
Notice how <IMG WIDTH=8 HEIGHT=8 ALIGN=BOTTOM ALT="tex2html_wrap_inline2476" SRC="img5.gif"> has been enclosed in <code>{}</code> since it is an "expandable" entity, <I>i.e.</I>, a defined macro.
<P>
<A NAME="Answer3">&#160;</A><H4><A NAME="SECTION00070030000000000000">Answer to exercise 3.</A></H4><A HREF="node7.html#Exercise3">Question.</A>
<P>
The author used 
<BLOCKQUOTE><PRE>\xymatrix{
 A \ar[r]^f \ar[dr]_{f;g}
  &amp; B \ar[d]^g \ar[dr]^{g;h} \\
  &amp; C \ar[r]_h &amp; D           }</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer4">&#160;</A><H4><A NAME="SECTION00070040000000000000">Answer to exercise 4.</A></H4><A HREF="node8.html#Exercise4">Question.</A>
<P>
The author entered 
<BLOCKQUOTE><PRE>\xymatrix{
 A \ar[d]_f \ar[r]^f
            &amp; B \ar[dl]|{i_B} \ar[d]^g \\
 B \ar[r]_g &amp; C }</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer5">&#160;</A><H4><A NAME="SECTION00070050000000000000">Answer to exercise 5.</A></H4><A HREF="node9.html#Exercise5">Question.</A>
<P>
The author did 
<BLOCKQUOTE><PRE>\xymatrix{
 x \ar@(ul,dl)[]|{id} \ar@/^/[rr]|f
 &amp;&amp; f(x) \ar@/^/[ll]|{f^{-1}} }</PRE></BLOCKQUOTE>
Note that both arrows are curved "above" relative to their direction.
<P>
<A NAME="Answer6">&#160;</A><H4><A NAME="SECTION00070060000000000000">Answer to exercise 6.</A></H4><A HREF="node12.html#Exercise6">Question.</A>
<P>
The author used the display 
<BLOCKQUOTE><PRE>\xymatrix{
 1 \ar[rr] ^-{1000000x}
   \ar[dr] _(.2){2000x} |!{[d];[rr]}\hole
                        &amp;&amp; 1000000 \\
 1000 \ar[r] _{2x}
      \ar[urr] _&gt;&gt;&gt;&gt;{x^2}
                        &amp; 2000 }</PRE></BLOCKQUOTE>
In particular notice how the break was specified to happen exactly where the two arrows cross. For an easier but not so general method see exercise&nbsp;<A HREF="#xcube">12</A> last in section&nbsp;<A HREF="node18.html#arrowspass">2.7</A>.
<P>
<A NAME="Answer7">&#160;</A><H4><A NAME="SECTION00070070000000000000">Answer to exercise 7.</A></H4><A HREF="node13.html#Exercise7">Question.</A>
<P>
The author typed 
<BLOCKQUOTE><PRE>\xymatrix@1{ A \ar[r]^*+[o][F-]{x} &amp; B }</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer8">&#160;</A><H4><A NAME="SECTION00070080000000000000">Answer to exercise 8.</A></H4><A HREF="node13.html#Exercise8">Question.</A>
<P>
The author did 
<BLOCKQUOTE><PRE>\xymatrix@1{
 A \ar @{/*\composite{{+}*{\times}}/} [rr]
       ^*+\txt{High\\label}
 &amp;&amp; B}</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer9">&#160;</A><H4><A NAME="SECTION00070090000000000000">Answer to exercise 9.</A></H4><A HREF="node14.html#Exercise9">Question.</A>
<P>
The author entered 
<BLOCKQUOTE><PRE>\xymatrix{
 A \ar @/^/ @{^{&lt;}-_{&gt;}} [r]
   \ar @/_/ @{{*}{x}{*}} [r] &amp; B }</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer10">&#160;</A><H4><A NAME="SECTION000700100000000000000">Answer to exercise 10.</A></H4><A HREF="node15.html#Exercise10">Question.</A>
<P>
The author typed 
<BLOCKQUOTE><PRE>\xymatrix@1{
 A \ar@/^/[r] \ar@/^/@&lt;-1ex&gt;[r] &amp; B }</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer11">&#160;</A><H4><A NAME="SECTION000700110000000000000">Answer to exercise 11.</A></H4><A HREF="node17.html#Exercise11">Question.</A>
<P>
The size: <I>t</I><code>+0</code> always has zero size.
<P>
<A NAME="Answer12">&#160;</A><H4><A NAME="SECTION000700120000000000000">Answer to exercise 12.</A></H4><A HREF="node18.html#Exercise12">Question.</A>
<P>
The author constructed 
<BLOCKQUOTE><PRE>\xymatrix@!0{
 &amp; \lambda\omega \ar@{-}[rr]\ar@{-}'[d][dd]
   &amp; &amp; \lambda C \ar@{-}[dd]
\\
 \lambda2 \ar@{-}[ur]\ar@{-}[rr]\ar@{-}[dd]
 &amp; &amp; \lambda P2 \ar@{-}[ur]\ar@{-}[dd]
\\
 &amp; \lambda\underline\omega \ar@{-}'[r][rr]
   &amp; &amp; \lambda P\underline\omega
\\
 \lambda{\to} \ar@{-}[rr]\ar@{-}[ur]
 &amp; &amp; \lambda P \ar@{-}[ur]
}</PRE></BLOCKQUOTE>
A special thing is added: <code>@!</code> forces rows and columns to be equally spaced as discussed in section&nbsp;<A HREF="node24.html#entriesresizing">3.3</A>; <code>@!0</code> furthermore makes the spacing ignore the entry sizes, giving a completely fixed grid. The gaps could also be made with the <code>!</code>... crossing notation of exercise&nbsp;<A HREF="#xintercept">6</A> last in section&nbsp;<A HREF="node12.html#arrowsplaces">2.1</A> but the above is shorter.
<P>
<A NAME="Answer13">&#160;</A><H4><A NAME="SECTION000700130000000000000">Answer to exercise 13.</A></H4><A HREF="node19.html#Exercise13">Question.</A>
<P>
The author typed 
<BLOCKQUOTE><PRE>\xymatrix@1{
 A \ar@&lt;-2pt&gt; `d[r] `[r] [r]
   \ar@&lt;+2pt&gt; `d[r] `[r] [r] &amp; B }</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer14">&#160;</A><H4><A NAME="SECTION000700140000000000000">Answer to exercise 14.</A></H4><A HREF="node20.html#Exercise14">Question.</A>
<P>
The author used 
<BLOCKQUOTE><PRE>\newdir{ &gt;}{{}*!/-5pt/@{&gt;}}</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer15">&#160;</A><H4><A NAME="SECTION000700150000000000000">Answer to exercise 15.</A></H4><A HREF="node20.html#Exercise15">Question.</A>
<P>
The author typed 
<BLOCKQUOTE><PRE>\xymatrix@1{
 A \ar[r] |-{\SelectTips{cm}{}\object@{&gt;&gt;}}
          |&gt;{\SelectTips{eu}{}\object@{&gt;}}
 &amp; B }</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer16">&#160;</A><H4><A NAME="SECTION000700160000000000000">Answer to exercise 16.</A></H4><A HREF="node22.html#Exercise16">Question.</A>
<P>
The author typed
<BLOCKQUOTE><PRE>\xymatrix{
 *=0{\bullet}
 \ar@/^/[dr]!U|1
 \ar@/^/[drr]!U|2
 \ar@/^/[drrr]!U|3
\\
 &amp;*+[F]\txt{x}
 &amp;*+[F]\txt{x\\x}
 &amp;*+[F]\txt{x\\x\\x}
}</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer17">&#160;</A><H4><A NAME="SECTION000700170000000000000">Answer to exercise 17.</A></H4><A HREF="node24.html#Exercise17">Question.</A>
<P>
The author entered the display
<BLOCKQUOTE><PRE>\xymatrix@dr@C=1pc{
 a \ar[r]\ar@{-&gt;&gt;}[d] &amp; a' \ar@{.&gt;&gt;}[d] \\
 b \ar@{.&gt;&gt;}[r]       &amp; b' }</PRE></BLOCKQUOTE>
<P>
<A NAME="Answer18">&#160;</A><H4><A NAME="SECTION000700180000000000000">Answer to exercise 18.</A></H4><A HREF="node26.html#Exercise18">Question.</A>
<P>
The author typed 
<BLOCKQUOTE><PRE>\xymatrix{
 A \ar[r] ^a=&quot;a&quot; &amp; B \ar[r] ^b=&quot;b&quot; &amp; C
  \ar @/^/ &quot;a&quot;;&quot;b&quot; }</PRE></BLOCKQUOTE>
Notice the use of both explicit base and target in the arrow between the labels.
<P>
<A NAME="Answer19">&#160;</A><H4><A NAME="SECTION000700190000000000000">Answer to exercise 19.</A></H4><A HREF="node27.html#Exercise19">Question.</A>
<P>
The author added the Xy-code
<BLOCKQUOTE><PRE>\save [].[dd].[ddrr].[rr]*[F.]\frm{}=&quot;back&quot;
 \restore</PRE></BLOCKQUOTE>
in the entry with <IMG WIDTH=23 HEIGHT=15 ALIGN=BOTTOM ALT="tex2html_wrap_inline2788" SRC="img71.gif">, and
<BLOCKQUOTE><PRE> \save [].[dd].[ddrr].[rr]*[F.]\frm{}
  \ar@{.} +UL;&quot;back&quot;+UL \ar@{.} +UR;&quot;back&quot;+UR
  \ar@{.} +DL;&quot;back&quot;+DL \ar@{.} +DR;&quot;back&quot;+DR
  \restore</PRE></BLOCKQUOTE>
in the entry with <IMG WIDTH=20 HEIGHT=15 ALIGN=BOTTOM ALT="tex2html_wrap_inline2790" SRC="img72.gif"> to produce
<BR><IMG WIDTH=244 HEIGHT=171 ALIGN=BOTTOM ALT="displaymath2792" SRC="img73.gif"><BR>
<P>
<P>&#160;<P ALIGN=RIGHT><FONT SIZE=1>Xy-pic User's Guide</FONT> <A HREF="18pt.html"><IMG SRC="./quest.gif" ALIGN=TOP HEIGHT=27 WIDTH=21 BORDER=0 ALT="?"></A><A NAME="tex2html463" HREF="node32.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="previous" SRC="./previous.gif"></A><A NAME="tex2html467" HREF="node28.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="previous" SRC="./previoussection.gif"></A><A NAME="tex2html469" HREF="xyguide-html.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="up" SRC="./up.gif"></A><A NAME="tex2html465" HREF="node34.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="next" SRC="./nextsection.gif"></A><A NAME="tex2html471" HREF="node34.html"><IMG WIDTH=27 HEIGHT=27 BORDER=0 ALIGN=ABSMIDDLE ALT="next" SRC="./next.gif"></A><P><ADDRESS>
<BR><HR>
<a href="COPYING/index.html">�/a> <a href="http://www.brics.dk/~krisrose/">Kristoffer H. Rose</a>
&lt;<a href="mailto:[email protected]">[email protected]</a>&gt;
January  6, 1997

/
<a href="http://www-dsed.llnl.gov/files/programs/unix/latex2html/manual/">LaTeX2<TT>HTML</TT>v96.1-h</a>
</FONT>

</ADDRESS>
</BODY>
</HTML>

Bell Labs OSI certified Powered by Plan 9

(Return to Plan 9 Home Page)

Copyright © 2021 Plan 9 Foundation. All Rights Reserved.
Comments to [email protected].