[css-syntax] Fix <an+b> parsing: '-n-3' is (-1, -3), not (-1, 3)

Author: SimonSapin

css-syntax/Overview.html

@@ -3601,7 +3601,7 @@ <h3 id=the-anb-type><span class=secno>6.2. </span> The <a
        <dt><a href="#ltinteger"><code><var>&lt;integer></var></code></a>
 
        <dd> <a href="#a"><var>A</var></a> is 0, <a href="#b"><var>B</var></a>
-        is the integer.
+        is the integer’s value.
 
        <dt><a
         href="#ltn-dimension"><code><var>&lt;n-dimension></var></code></a>
@@ -3619,13 +3619,19 @@ <h3 id=the-anb-type><span class=secno>6.2. </span> The <a
        <dt><code>'+'? <a
         href="#ltndashdigit-ident"><var>&lt;ndashdigit-ident></var></a></code>
 
+       <dd> <a href="#a"><var>A</var></a> is the dimension's value or 1,
+        respectively. <a href="#b"><var>B</var></a> is the dimension's unit
+        or ident's value, respectively, with the first character removed and
+        the remainder interpreted as a base-10 number. <span class=note>B is
+        negative.</span>
+
        <dt><a
         href="#ltdashndashdigit-ident"><code><var>&lt;dashndashdigit-ident></var></code></a>
 
-       <dd> <a href="#a"><var>A</var></a> is the dimension's value, 1, or -1,
-        respectively. <a href="#b"><var>B</var></a> is the dimension's unit
-        or ident's value, as appropriate, with the first two characters
-        removed and the remainder interpreted as a base-10 number.
+       <dd> <a href="#a"><var>A</var></a> is -1. <a
+        href="#b"><var>B</var></a> is the ident's value, with the first two
+        characters removed and the remainder interpreted as a base-10 number.
+        <span class=note>B is negative.</span>
 
        <dt><code><a href="#ltn-dimension"><var>&lt;n-dimension></var></a> <a
         href="#ltsigned-integer"><var>&lt;signed-integer></var></a></code>
@@ -3637,7 +3643,7 @@ <h3 id=the-anb-type><span class=secno>6.2. </span> The <a
         href="#ltsigned-integer"><var>&lt;signed-integer></var></a></code>
 
        <dd> <a href="#a"><var>A</var></a> is the dimension's value, 1, or -1,
-        respectively. <a href="#b"><var>B</var></a> is the integer.
+        respectively. <a href="#b"><var>B</var></a> is the integer’s value.
 
        <dt><code><a href="#ltn-dimension"><var>&lt;n-dimension></var></a>
         ['+' | '-'] <a
@@ -3650,9 +3656,10 @@ <h3 id=the-anb-type><span class=secno>6.2. </span> The <a
         href="#ltsignless-integer"><var>&lt;signless-integer></var></a></code>
 
        <dd> <a href="#a"><var>A</var></a> is the dimension's value, 1, or -1,
-        respectively. <a href="#b"><var>B</var></a> is the integer. If a
-        ‘<code class=property>-</code>’ was provided between the two, <a
-        href="#b"><var>B</var></a> is instead the negation of the integer.
+        respectively. <a href="#b"><var>B</var></a> is the integer’s value.
+        If a ‘<code class=property>-</code>’ was provided between the
+        two, <a href="#b"><var>B</var></a> is instead the negation of the
+        integer’s value.
       </dl>
 
       <h2 id=rule-defs><span class=secno>7. </span> Defining Grammars for

css-syntax/Overview.src.html

@@ -2530,31 +2530,43 @@ <h3 id="the-anb-type">
 
 		<dt><code><var>&lt;integer></var></code>
 		<dd>
-			<var>A</var> is 0, <var>B</var> is the integer.
+			<var>A</var> is 0, <var>B</var> is the integer’s value.
 
 		<dt><code><var>&lt;n-dimension></var></code>
 		<dt><code>'+'? n</code>
 		<dt><code>-n</code>
 		<dd>
-			<var>A</var> is the dimension's value, 1, or -1, respectively. <var>B</var> is 0.
+			<var>A</var> is the dimension's value, 1, or -1, respectively.
+			<var>B</var> is 0.
 
 		<dt><code><var>&lt;ndashdigit-dimension></var></code>
 		<dt><code>'+'? <var>&lt;ndashdigit-ident></var></code>
+		<dd>
+			<var>A</var> is the dimension's value or 1, respectively.
+			<var>B</var> is the dimension's unit or ident's value, respectively,
+			with the first character removed and the remainder interpreted as a base-10 number.
+			<span class=note>B is negative.</span>
+
 		<dt><code><var>&lt;dashndashdigit-ident></var></code>
 		<dd>
-			<var>A</var> is the dimension's value, 1, or -1, respectively. <var>B</var> is the dimension's unit or ident's value, as appropriate, with the first two characters removed and the remainder interpreted as a base-10 number.
+			<var>A</var> is -1.
+			<var>B</var> is the ident's value, with the first two characters removed and the remainder interpreted as a base-10 number.
+			<span class=note>B is negative.</span>
 
 		<dt><code><var>&lt;n-dimension></var> <var>&lt;signed-integer></var></code>
 		<dt><code>'+'? n <var>&lt;signed-integer></var></code>
 		<dt><code>-n <var>&lt;signed-integer></var></code>
 		<dd>
-			<var>A</var> is the dimension's value, 1, or -1, respectively. <var>B</var> is the integer.
+			<var>A</var> is the dimension's value, 1, or -1, respectively.
+			<var>B</var> is the integer’s value.
 
 		<dt><code><var>&lt;n-dimension></var> ['+' | '-'] <var>&lt;signless-integer></var></code>
 		<dt><code>'+'? n ['+' | '-'] <var>&lt;signless-integer></var></code>
 		<dt><code>-n ['+' | '-'] <var>&lt;signless-integer></var></code>
 		<dd>
-			<var>A</var> is the dimension's value, 1, or -1, respectively. <var>B</var> is the integer. If a '-' was provided between the two, <var>B</var> is instead the negation of the integer.
+			<var>A</var> is the dimension's value, 1, or -1, respectively.
+			<var>B</var> is the integer’s value.
+			If a '-' was provided between the two, <var>B</var> is instead the negation of the integer’s value.
 	</dl>