11<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
22<html lang="en">
3- <!-- $Id: conform.src,v 1.20 1997-10-20 02:59:54 ian Exp $ -->
3+ <!-- $Id: conform.src,v 1.21 1997-10-29 04:38:25 ian Exp $ -->
44<HEAD>
55<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
66<TITLE>Definitions and document conventions</TITLE>
7- <LINK rel="next" href="syndata .html">
7+ <LINK rel="next" href="process .html">
88<LINK rel="previous" href="intro.html">
99<LINK rel="STYLESHEET" href="style/default.css" type="text/css">
1010</HEAD>
@@ -23,75 +23,13 @@ these elements of the document language. Examples of elements in HTML
2323include "P" (for structuring paragraphs), "TABLE" (for creating
2424tables), "OL" (for creating ordered lists), etc.
2525
26+ <H3><a name="inheritance">Inheritance of property values</a></h3>
2627
27- <H3><a name="doctree">Document tree, parent, child, descendant,
28- ancestor</a></H3>
29-
30- <P>CSS makes use of the fact that a document in the document language
31- can be thought of as a tree: every element except one has exactly one
32- <span class="index-def" title="parent">parent</span> element. (See the
33- SGML (<a href="refs.html#ref-ISO8879">[ISO8879]</a>) and XML (<a
34- href="refs.html#ref-XML">[XML]</a>) specifications for the
35- definition of parent.) The one exception is the <span
36- class="index-def" title="root">root</span> element, which has no
37- parent. An element A is called a <span class="index-def"
38- title="child">child</span> of an element B, if and only if B is the
39- parent of A.
40-
41- <P>An element A is called a <span class="index-def"
42- title="ancestor">ancestor</span> of an element B, if either (1) A is
43- the parent B, or (2) A is the parent of some element C that is an
44- ancestor of B.
45-
46- <P>An element A is called a <span class="index-def"
47- title="descendant">descendant</span> of an element B, if and only if B
48- is an ancestor of A.
49-
50- <div class="example"><P>
51- For example, the following HTML document:
52- <PRE>
53- <HTML>
54- <TITLE>My home page</TITLE>
55- <BODY>
56- <H1>My home page</H1>
57- <P>Welcome to my home page! Let me tell you about my favorite
58- composers:
59- <UL>
60- <LI> Elvis Costello
61- <LI> Johannes Brahms
62- <LI> Georges Brassens
63- </UL>
64- </BODY>
65- </HTML>
66- </PRE>
67-
68- <P>results in the following tree:</P>
69-
70- <IMG src="images/doctree.gif" alt="Sample document tree">
71-
72- <P>Notice that although the source program does not explicitly refer
73- to the HEAD element, it is inferred during parsing and becomes part of
74- the document tree.
75- </div>
76-
77- <!--
78- <P>Notice in the previous example that the tree illustration does not
79- refer to the text this program: the title text, the paragraph text, and
80- the list item text.
81- -->
82-
83- <H3><span class="index-def" title="inheritance">Inheritance of
84- property values</span></H3>
85-
86- <P>CSS works, basically, by converting the document tree to a tree of
87- rendering objects that are characterized by properties. A property has
88- a name, such as 'font-weight' and a value, for example 'bold'. All
89- rendering objects have the same properties, but the values may
90- differ. The values can be set explicitly, but if they are not, the
91- values are either inherited, or set to an "initial" value.
92-
93- <P>If a value is inherited, it means the value is the same as the
94- value in the rendering object for the parent element.
28+ <P>Property values may be set explicitly, inherited, or have an
29+ initial value. If a value is <span class="index-def"
30+ title="inheritance of property values">inherited</span> inherited, it
31+ means the value is the same as the value in the rendering object for
32+ the parent element.
9533
9634<div class="example"><P>
9735Suppose there is an H1 element with an emphasized element inside:
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