From 8b7a71d8895e009c8d74a1255299818d54016b48 Mon Sep 17 00:00:00 2001
From: Mark Pilgrim <mark@diveintomark.org>
Date: Fri, 25 Sep 2009 23:55:35 -0400
Subject: [PATCH] make repeated rules uniform between chapters

---
 regular-expressions.html | 11 ++++++-----
 unit-testing.html        |  4 ++--
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/regular-expressions.html b/regular-expressions.html
index 549544b..f384049 100755
--- a/regular-expressions.html
+++ b/regular-expressions.html
@@ -84,11 +84,12 @@ body{counter-reset:h1 5}
 </ul>
 <p>The following are some general rules for constructing Roman numerals:
 <ul>
-<li>Characters are additive. <code>I</code> is <code>1</code>, <code>II</code> is <code>2</code>, and <code>III</code> is <code>3</code>. <code>VI</code> is <code>6</code> (literally, &#8220;<code>5</code> and <code>1</code>&#8221;), <code>VII</code> is <code>7</code>, and <code>VIII</code> is <code>8</code>.
-<li>The tens characters (<code>I</code>, <code>X</code>, <code>C</code>, and <code>M</code>) can be repeated up to three times. At <code>4</code>, you need to subtract from the next highest fives character. You can&#8217;t represent <code>4</code> as <code>IIII</code>; instead, it is represented as <code>IV</code> (&#8220;<code>1</code> less than <code>5</code>&#8221;). The number <code>40</code> is written as <code>XL</code> (<code>10</code> less than <code>50</code>), <code>41</code> as <code>XLI</code>, <code>42</code> as <code>XLII</code>, <code>43</code> as <code>XLIII</code>, and then <code>44</code> as <code>XLIV</code> (<code>10</code> less than <code>50</code>, then <code>1</code> less than <code>5</code>).
-<li>Similarly, at <code>9</code>, you need to subtract from the next highest tens character: <code>8</code> is <code>VIII</code>, but <code>9</code> is <code>IX</code> (<code>1</code> less than <code>10</code>), not <code>VIIII</code> (since the <code>I</code> character can not be repeated four times). The number <code>90</code> is <code>XC</code>, <code>900</code> is <code>CM</code>.
-<li>The fives characters can not be repeated. The number <code>10</code> is always represented as <code>X</code>, never as <code>VV</code>. The number <code>100</code> is always <code>C</code>, never <code>LL</code>.
-<li>Roman numerals are always written highest to lowest, and read left to right, so the order of characters matters very much. <code>DC</code> is <code>600</code>; <code>CD</code> is a completely different number (<code>400</code>, <code>100</code> less than <code>500</code>). <code>CI</code> is <code>101</code>; <code>IC</code> is not even a valid Roman numeral (because you can&#8217;t subtract <code>1</code> directly from <code>100</code>; you would need to write it as <code>XCIX</code>, for <code>10</code> less than <code>100</code>, then <code>1</code> less than <code>10</code>).
+<ol>
+<li>Sometimes characters are additive. <code>I</code> is <code>1</code>, <code>II</code> is <code>2</code>, and <code>III</code> is <code>3</code>. <code>VI</code> is <code>6</code> (literally, &#8220;<code>5</code> and <code>1</code>&#8221;), <code>VII</code> is <code>7</code>, and <code>VIII</code> is <code>8</code>.
+<li>The tens characters (<code>I</code>, <code>X</code>, <code>C</code>, and <code>M</code>) can be repeated up to three times. At <code>4</code>, you need to subtract from the next highest fives character. You can't represent <code>4</code> as <code>IIII</code>; instead, it is represented as <code>IV</code> (&#8220;<code>1</code> less than <code>5</code>&#8221;). <code>40</code> is written as <code>XL</code> (&#8220;<code>10</code> less than <code>50</code>&#8221;), <code>41</code> as <code>XLI</code>, <code>42</code> as <code>XLII</code>, <code>43</code> as <code>XLIII</code>, and then <code>44</code> as <code>XLIV</code> (&#8220;<code>10</code> less than <code>50</code>, then <code>1</code> less than <code>5</code>&#8221;).
+<li>Sometimes characters are&hellip; the opposite of additive. By putting certain characters before others, you subtract from the final value. For example, at <code>9</code>, you need to subtract from the next highest tens character: <code>8</code> is <code>VIII</code>, but <code>9</code> is <code>IX</code> (&#8220;<code>1</code> less than <code>10</code>&#8221;), not <code>VIIII</code> (since the <code>I</code> character can not be repeated four times). <code>90</code> is <code>XC</code>, <code>900</code> is <code>CM</code>.
+<li>The fives characters can not be repeated. <code>10</code> is always represented as <code>X</code>, never as <code>VV</code>. <code>100</code> is always <code>C</code>, never <code>LL</code>.
+<li>Roman numerals are read left to right, so the order of characters matters very much. <code>DC</code> is <code>600</code>; <code>CD</code> is a completely different number (<code>400</code>, &#8220;<code>100</code> less than <code>500</code>&#8221;). <code>CI</code> is <code>101</code>; <code>IC</code> is not even a valid Roman numeral (because you can't subtract <code>1</code> directly from <code>100</code>; you would need to write it as <code>XCIX</code>, &#8220;<code>10</code> less than <code>100</code>, then <code>1</code> less than <code>10</code>&#8221;).
 </ul>
 <h3 id=thousands>Checking For Thousands</h3>
 <p>What would it take to validate that an arbitrary string is a valid Roman numeral?  Let&#8217;s take it one digit at a time. Since Roman numerals are always written highest to lowest, let&#8217;s start with the highest: the thousands place. For numbers 1000 and higher, the thousands are represented by a series of <code>M</code> characters.
diff --git a/unit-testing.html b/unit-testing.html
index 05826cf..0fbdbc2 100755
--- a/unit-testing.html
+++ b/unit-testing.html
@@ -705,13 +705,13 @@ OK</samp></pre>
 
 <p>As you saw in <a href=regular-expressions.html#romannumerals>Case Study: Roman Numerals</a>, there are several simple rules for constructing a Roman numeral, using the letters <code>M</code>, <code>D</code>, <code>C</code>, <code>L</code>, <code>X</code>, <code>V</code>, and <code>I</code>. Let's review the rules:
 
-<ol>
+<ul>
 <li>Sometimes characters are additive. <code>I</code> is <code>1</code>, <code>II</code> is <code>2</code>, and <code>III</code> is <code>3</code>. <code>VI</code> is <code>6</code> (literally, &#8220;<code>5</code> and <code>1</code>&#8221;), <code>VII</code> is <code>7</code>, and <code>VIII</code> is <code>8</code>.
 <li>The tens characters (<code>I</code>, <code>X</code>, <code>C</code>, and <code>M</code>) can be repeated up to three times. At <code>4</code>, you need to subtract from the next highest fives character. You can't represent <code>4</code> as <code>IIII</code>; instead, it is represented as <code>IV</code> (&#8220;<code>1</code> less than <code>5</code>&#8221;). <code>40</code> is written as <code>XL</code> (&#8220;<code>10</code> less than <code>50</code>&#8221;), <code>41</code> as <code>XLI</code>, <code>42</code> as <code>XLII</code>, <code>43</code> as <code>XLIII</code>, and then <code>44</code> as <code>XLIV</code> (&#8220;<code>10</code> less than <code>50</code>, then <code>1</code> less than <code>5</code>&#8221;).
 <li>Sometimes characters are&hellip; the opposite of additive. By putting certain characters before others, you subtract from the final value. For example, at <code>9</code>, you need to subtract from the next highest tens character: <code>8</code> is <code>VIII</code>, but <code>9</code> is <code>IX</code> (&#8220;<code>1</code> less than <code>10</code>&#8221;), not <code>VIIII</code> (since the <code>I</code> character can not be repeated four times). <code>90</code> is <code>XC</code>, <code>900</code> is <code>CM</code>.
 <li>The fives characters can not be repeated. <code>10</code> is always represented as <code>X</code>, never as <code>VV</code>. <code>100</code> is always <code>C</code>, never <code>LL</code>.
 <li>Roman numerals are read left to right, so the order of characters matters very much. <code>DC</code> is <code>600</code>; <code>CD</code> is a completely different number (<code>400</code>, &#8220;<code>100</code> less than <code>500</code>&#8221;). <code>CI</code> is <code>101</code>; <code>IC</code> is not even a valid Roman numeral (because you can't subtract <code>1</code> directly from <code>100</code>; you would need to write it as <code>XCIX</code>, &#8220;<code>10</code> less than <code>100</code>, then <code>1</code> less than <code>10</code>&#8221;).
-</ol>
+</ul>
 
 <p>Thus, one useful test would be to ensure that the <code>from_roman()</code> function should fail when you pass it a string with too many repeated numerals. How many is &#8220;too many&#8221; depends on the numeral.