Update documentation for new features

doc/cmdref.sgm

@@ -58,8 +58,8 @@
           Normal labels are <emphasis>defined</emphasis> by
           prefixing a line with the label name and then a colon
           (e.g., <literal>label:</literal>).  Anonymous labels
-          are defined by prefixing a line with an asterisk
-          (e.g., <literal>*</literal>).
+          are defined by prefixing a line with just a colon or
+          with an asterisk.
         </para>
         <para>
           Temporary labels are only reachable from inside the
@@ -103,9 +103,9 @@
         bytes of 16-bit values, respectively.
       </para>
       <para>
-        Use brackets [ ] instead of parentheses ( ) when grouping
-        arithmetic operations, as the parentheses are needed for the
-        indirect addressing modes.
+        You may use parentheses ( ), brackets [ ], or curly braces { }
+        to group arithmetic expressions. Note that a fully parenthesized
+        expression will be interpreted as an indirect addressing mode.
       </para>
       <para>
         Examples:

doc/ophismanual.sgm

@@ -20,7 +20,7 @@
   <bookinfo>
     <title>Programming with Ophis</title>
     <author><firstname>Michael</firstname><surname>Martin</surname></author>
-    <copyright><year>2006-2024</year><holder>Michael Martin</holder></copyright>
+    <copyright><year>2006-2026</year><holder>Michael Martin</holder></copyright>
   </bookinfo>
   &pre1;
   <part label="I">

doc/preface.sgm

@@ -87,7 +87,9 @@
       <emphasis>that</emphasis>, enough bug reports and bug fixes had
       trickled in to justify a fresh release, and 2.2 was published in
       2024&mdash;a lightly polished update that now fit more neatly
-      into the Python toolchains of the 2020s.
+      into the Python toolchains of the 2020s. 2.3, in 2026, fixed up
+      some infelicities and inconveniences that I finally decided I
+      didn't need to put up with any more.
     </para>
     <para>
       In the twenty years since I first started this project, I've

doc/tutor2.sgm

@@ -57,8 +57,8 @@ _next:  .word 0              ; End of program
         Anonymous labels are a way to handle short-ranged branches
         without having to come up with names for the then and else
         branches, for brief loops, and other such purposes.  To define
-        an anonymous label, use an asterisk.  To refer to an anonymous
-        label, use a series of <literal>+</literal>
+        an anonymous label, use a bare colon or an asterisk.  To refer
+        to an anonymous label, use a series of <literal>+</literal>
         or <literal>-</literal> signs.  <literal>+</literal> refers to
         the next anonymous label, <literal>++</literal> the label
         after that, etc.  Likewise, <literal>-</literal> is the most
@@ -74,7 +74,7 @@ _next:  .word 0              ; End of program
         jsr $ffd2
         inx
         bne -
-*       rts
+:       rts
 </programlisting>
 
     <para>

doc/tutor6.sgm

@@ -100,7 +100,7 @@ _done:  rts
         </row>
       </thead>
       <tbody>
-        <row><entry><literal>[ ]</literal></entry><entry>Parenthesized expressions</entry></row>
+        <row><entry><literal>{ } [ ] ( )</literal></entry><entry>Parenthesized expressions</entry></row>
         <row><entry><literal>&lt; &gt;</literal></entry><entry>Byte selection (low, high)</entry></row>
         <row><entry><literal>* /</literal></entry><entry>Multiply, divide</entry></row>
         <row><entry><literal>+ -</literal></entry><entry>Add, subtract</entry></row>
@@ -108,10 +108,9 @@ _done:  rts
       </tbody>
     </tgroup>
   </table>
+
   <para>
-    Note that brackets, not parentheses, are used to group arithmetic
-    operations.  Parentheses are reserved for the indirect addressing
-    modes.
+    Until version 2.3, only brackets were allowed to parenthesize expressions.
   </para>
 
   <para>