replace 'constituent' with 'appears in'

this makes Respec unhappy, because 'appears in' is currently not defined,
but including the definition will be for another PR.
This keeps this PR more "localized".

Author: pchampin

spec/index.html

@@ -909,13 +909,6 @@ <h3>Triple Terms</h3>
       Every <a>triple</a> whose <a>object</a> is not a <a>triple term</a> SHOULD NOT
       use <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#reifies</code> (<code>rdf:reifies</code>)
       as its <a>predicate</a>.</p>
-
-    <p>The <dfn data-lt="constituent">constituent terms</dfn> (or simply constituents)
-      of a [=triple term=] or an [=RDF triple=] are its [=subject=], its [=predicate=], its [=object=],
-      and all the [=constituent terms=] of its [=object=] if it is itself a [=triple term=].
-      By extension, the [=constituent terms=] of an [=RDF graph=] are all the constituent terms of its triples.
-    </p>
-
   </section>
 
   <section id="graph-isomorphism">
@@ -1544,8 +1537,8 @@ <h2>From [=Full=] to [=Classic=]</h2>
 
     <p>
       Encoding an [=RDF graph=] to ensure that it is consumable by an RDF [=Classic=] implementation is called <dfn data-lt="classicize|classicized">classicizing</dfn> it.
-      [=Classicizing=] consists of repeating the following steps until no [=constituent=] of the graph is a [=triple term=], and the graph is therefore compliant with RDF [=Classic=]: picking a [=triple term=] <var>tt</var> that is a [=constituent terms=] of the graph; minting a fresh [=blank node=] <var>b</var>
-      (i.e., a blank node not yet in use in the graph); replacing <var>tt</var> with <var>b</var> in all the triples of the graph having <var>tt</var> in their [=constituents=];
+      [=Classicizing=] consists of repeating the following steps until no [=triple term=] [=appears=] in the graph, and the graph is therefore compliant with RDF [=Classic=]: picking a [=triple term=] <var>tt</var> that [=appears=] in the graph; minting a fresh [=blank node=] <var>b</var>
+      (i.e., a blank node not yet in use in the graph); replacing all occurrences of <var>tt</var> [=appearing=] in the graph with <var>b</var>;
       and then adding the following triples to the graph (where <var>s</var>, <var>p</var>, and <var>o</var> are respectively the [=subject=], [=predicate=] and [=object=] of <var>tt</var>):
     </p>
     <ul>
@@ -1555,7 +1548,7 @@ <h2>From [=Full=] to [=Classic=]</h2>
       <li>(<var>b</var>, `rdf:ttObject`, <var>o</var>)
     </ul>
 
-    <p>Note that this transformation is <em>information preserving</em> only when the input graph either has no [=triple term=] in its [=constituents=],
+    <p>Note that this transformation is <em>information preserving</em> only when the input graph either has no [=triple term=] [=appearing=] in it,
       or contains no [=asserted=] triple (<var>b</var>, `rdf:type`, `rdf:TripleTerm`) where <var>b</var> is a [=blank node=].
       Implementations encountering this situation MUST report an error.
       This limitation is discussed in Section <a href="#section-classicize-caveat"></a>.
@@ -1607,15 +1600,14 @@ <h2>From [=Classic=] to [=Full=]</h2>
 
     <p>Reverting a [=classicized=] graph to its original form consists of locating
       each [=asserted=] triple (<var>b</var>, `rdf:type`, `rdf:TripleTerm`)
-      that has a [=blank node=] <var>b</var> as its subject, 
-      along with the three associated [=asserted=] triples 
+      that has a [=blank node=] <var>b</var> as its subject,
+      along with the three associated [=asserted=] triples
       that have the same [=blank node=] <var>b</var> as their subjects, i.e.,
       (<var>b</var>, `rdf:ttSubject`, <var>s</var>),
       (<var>b</var>, `rdf:ttPredicate`, <var>p</var>),
       and (<var>b</var>, `rdf:ttObject`, <var>o</var>);
       removing these four triples from the graph;
-      and replacing all remaining occurrences of <var>b</var> 
-      as a [=constituent term=] of the graph 
+      and replacing all remaining occurrences of <var>b</var> [=appearing=] in the graph
       with the triple term (<var>s</var>, <var>p</var>, <var>o</var>).
     </p>
 
@@ -1626,7 +1618,7 @@ <h2>From [=Classic=] to [=Full=]</h2>
       is missing or duplicated).
       An implementation MUST also report an error if the input graph contains
       at the same time a [=triple term=] and an [=asserted triple=]
-      (<var>b</var>, `rdf:type`, `rdf:TripleTerm`) 
+      (<var>b</var>, `rdf:type`, `rdf:TripleTerm`)
       where <var>b</var> is the same [=blank node=].
       Note that none of these situations can occur if the input graph was produced by the [=classicize=] transformation.
     </p>
@@ -1644,7 +1636,7 @@ <h2>From [=Classic=] to [=Full=]</h2>
     <h2>Limitations</h2>
 
     <p>The two transformations above explicitly do not support graphs or datasets containing at the same time a [=triple term=] and an [=asserted triple=]
-      (<var>b</var>, `rdf:type`, `rdf:TripleTerm`) 
+      (<var>b</var>, `rdf:type`, `rdf:TripleTerm`)
       where <var>b</var> is a [=blank node=].
       This means that the [=classicize=] transformation is not <em>strictly</em> universal.
     </p>