[selectors] Wordsmith Pseudo-classes section (the name of a pseudo-class is not a function including its arguments) and restore some information lost in <https://hg.csswg.org/drafts/diff/34e3c6a4ac96/selectors/Overview.bs>.

Author: fantasai

selectors/Overview.bs

@@ -22,7 +22,7 @@ Abstract: Selectors Level 4 describes the selectors that already exist in [[!SEL
 At Risk: the column combinator
 At Risk: the '':drop()'' pseudo-class
 At Risk: the '':read-write'' pseudo-class
-Ignored Terms: Document, DocumentFragment, math, h1, shadow tree, box tree, query(), quirks mode, button, a, span, object, p, div, q, area, link, label, input, html, em, li, ol, pre
+Ignored Terms: function token, Document, DocumentFragment, math, h1, shadow tree, query(), quirks mode, button, a, span, object, p, div, q, area, link, label, input, html, em, li, ol, pre
 Link Defaults: dom-core-ls (interface) Document
 </pre>
 <style>
@@ -514,7 +514,7 @@ Structure and Terminology</h3>
 	is a sequence of <a>simple selectors</a>
 	that are not separated by a <a>combinator</a>.
 	If it contains a <a>type selector</a> or <a>universal selector</a>,
-	that selector comes first in the sequence.
+	that selector must come first in the sequence.
 	Only one type selector or universal selector is allowed in the sequence.
 
 	A <dfn id="simple" export>simple selector</dfn> represents an aspect of an element to be matched against.
@@ -793,7 +793,7 @@ Guidance on Mapping Document Languages to DOM</h4>
 <h3 id="scoping">
 Scoped Selectors</h3>
 
-	Some host applications may choose to <dfn export lt="scope | scoped selector">scope</dfn> selectors
+	Some host applications may choose to <dfn export lt="scoped selector" local-lt="scope">scope</dfn> selectors
 	to a particular subtree or fragment of the document.
 	The root of the scoping subtree is called the <dfn export>scoping root</dfn>,
 	and may be either a true element (the <dfn export>scoping element</dfn>)
@@ -893,36 +893,44 @@ Absolutizing a Relative Selector</h4>
 <h3 id="pseudo-classes">
 Pseudo-classes</h3>
 
-	The <dfn export>pseudo-class</dfn> concept is introduced to permit selection based on
+	<dfn export lt="pseudo-class">Pseudo-classes</dfn> are <a>simple selectors</a>
+	that permit selection based on
 	information that lies outside of the document tree
 	or that can be awkward or impossible to express using the other simple selectors.
+	They can also be dynamic,
+	in the sense that an element can acquire or lose a pseudo-class
+	while a user interacts with the document,
+	without the document itself changing.
+	<a>Pseudo-classes</a> do not appear in or modify the document source or document tree.
 
 	The syntax of a <a>pseudo-class</a>
-	is a ":" (U+003A COLON)
-	followed by the name of the <a>pseudo-class</a>,
-	which is either an <a>identifier</a>,
-	or in the case of a	<dfn export>functional pseudo-class</dfn>,
-	a function potentially containing arguments between parentheses
-	(similar to CSS functions).
+	consists of a ":" (U+003A COLON)
+	followed by the name of the <a>pseudo-class</a>
+	as a CSS <a>identifier</a>,
+	and, in the case of a <dfn export>functional pseudo-class</dfn>,
+	a pair of parentheses containing its arguments.
+
+	<p class="example">
+		For example, '':valid'' is a regular pseudo-class,
+		and  '':lang()'' is a <a>functional pseudo-class</a>.
 
+	Like all CSS keywords, <a>pseudo-class</a> names are <a>ASCII case-insensitive</a>.
 	No <a>white space</a> is allowed between the colon and the name of the <a>pseudo-class</a>,
-	and as usual for CSS syntax,
-	there are no spaces between the function name and its opening parenthesis.
-	As usual for CSS syntax,
-	<a>white space</a> is allowed arond the arguments between the parentheses
-	of a functional pseudo-class,
+	nor, as usual for CSS syntax,
+	between a <a>functional pseudo-class</a>’s name and its opening parenthesis
+	(which thus form a CSS <a>function token</a>).
+	Also as usual,
+	<a>white space</a> is allowed around the arguments inside the parentheses
+	of a functional pseudo-class
 	unless otherwise specified.
 
-	<a>Pseudo-classes</a> are identical to any other type of <a>simple selector</a>:
-	they're allowed in all <a>compound selectors</a> contained in a selector,
+	Like other <a>simple selectors</a>,
+	<a>pseudo-classes</a> are allowed in all <a>compound selectors</a> contained in a selector,
 	and must follow the <a>type selector</a> or <a>universal selector</a>, if present.
-	<a>Pseudo-class</a> names are <a>ASCII case-insensitive</a>.
-	Some <a>pseudo-classes</a> are mutually exclusive
+
+	Note: Some <a>pseudo-classes</a> are mutually exclusive
 	(such that a <a>compound selector</a> containing them, while valid, will never match anything),
 	while others can apply simultaneously to the same element.
-	<a>Pseudo-classes</a> may be dynamic,
-	in the sense that an element can acquire or lose a pseudo-class
-	while a user interacts with the document.
 
 <h3 id="pseudo-elements">Pseudo-elements</h3>
 
@@ -3183,7 +3191,7 @@ Grammar</h2>
 	The productions in uppercase are defined by CSS Syntax [[!CSS3SYN]],
 	and correspond to the tokens of the same name.
 	Literal strings correspond to delim tokens with the given value.
-	Unlike other grammars in CSS, whitespace is not ignored
+	Unlike other grammars in CSS, whitespace is not ignored.
 	The production "S" represents a whitespace token.
 	The wqname_prefix production comes from the Namespaces spec [[!CSS3NAMESPACE]]