src/Doc/Isar_Ref/Outer_Syntax.thy

   \<^medskip>
   The categories for named tokens are defined once and for all as follows.
 
   \begin{center}
   \begin{supertabular}{rcl}
-    @{syntax_def ident} & = & \<open>letter (subscript\<^sup>? quasiletter)\<^sup>*\<close> \\
-    @{syntax_def longident} & = & \<open>ident(\<close>\<^verbatim>\<open>.\<close>\<open>ident)\<^sup>+\<close> \\
-    @{syntax_def symident} & = & \<open>sym\<^sup>+  |\<close>~~\<^verbatim>\<open>\\<close>\<^verbatim>\<open><\<close>\<open>ident\<close>\<^verbatim>\<open>>\<close> \\
+    @{syntax_def short_ident} & = & \<open>letter (subscript\<^sup>? quasiletter)\<^sup>*\<close> \\
+    @{syntax_def long_ident} & = & \<open>short_ident(\<close>\<^verbatim>\<open>.\<close>\<open>short_ident)\<^sup>+\<close> \\
+    @{syntax_def sym_ident} & = & \<open>sym\<^sup>+  |\<close>~~\<^verbatim>\<open>\\<close>\<^verbatim>\<open><\<close>\<open>short_ident\<close>\<^verbatim>\<open>>\<close> \\
     @{syntax_def nat} & = & \<open>digit\<^sup>+\<close> \\
     @{syntax_def float} & = & @{syntax_ref nat}\<^verbatim>\<open>.\<close>@{syntax_ref nat}~~\<open>|\<close>~~\<^verbatim>\<open>-\<close>@{syntax_ref nat}\<^verbatim>\<open>.\<close>@{syntax_ref nat} \\
-    @{syntax_def var} & = & \<^verbatim>\<open>?\<close>\<open>ident  |\<close>~~\<^verbatim>\<open>?\<close>\<open>ident\<close>\<^verbatim>\<open>.\<close>\<open>nat\<close> \\
-    @{syntax_def typefree} & = & \<^verbatim>\<open>'\<close>\<open>ident\<close> \\
-    @{syntax_def typevar} & = & \<^verbatim>\<open>?\<close>\<open>typefree  |\<close>~~\<^verbatim>\<open>?\<close>\<open>typefree\<close>\<^verbatim>\<open>.\<close>\<open>nat\<close> \\
+    @{syntax_def term_var} & = & \<^verbatim>\<open>?\<close>\<open>short_ident  |\<close>~~\<^verbatim>\<open>?\<close>\<open>short_ident\<close>\<^verbatim>\<open>.\<close>\<open>nat\<close> \\
+    @{syntax_def type_ident} & = & \<^verbatim>\<open>'\<close>\<open>short_ident\<close> \\
+    @{syntax_def type_var} & = & \<^verbatim>\<open>?\<close>\<open>type_ident  |\<close>~~\<^verbatim>\<open>?\<close>\<open>type_ident\<close>\<^verbatim>\<open>.\<close>\<open>nat\<close> \\
     @{syntax_def string} & = & \<^verbatim>\<open>"\<close> \<open>\<dots>\<close> \<^verbatim>\<open>"\<close> \\
     @{syntax_def altstring} & = & \<^verbatim>\<open>`\<close> \<open>\<dots>\<close> \<^verbatim>\<open>`\<close> \\
     @{syntax_def cartouche} & = & @{verbatim "\<open>"} \<open>\<dots>\<close> @{verbatim "\<close>"} \\
     @{syntax_def verbatim} & = & \<^verbatim>\<open>{*\<close> \<open>\<dots>\<close> \<^verbatim>\<open>*}\<close> \\[1ex]
 

           &   & \<^verbatim>\<open>\<Lambda>\<close>~~\<open>|\<close>~~\<^verbatim>\<open>\<Xi>\<close>~~\<open>|\<close>~~\<^verbatim>\<open>\<Pi>\<close>~~\<open>|\<close>~~\<^verbatim>\<open>\<Sigma>\<close>~~\<open>|\<close> \\
           &   & \<^verbatim>\<open>\<Upsilon>\<close>~~\<open>|\<close>~~\<^verbatim>\<open>\<Phi>\<close>~~\<open>|\<close>~~\<^verbatim>\<open>\<Psi>\<close>~~\<open>|\<close>~~\<^verbatim>\<open>\<Omega>\<close> \\
   \end{supertabular}
   \end{center}
 
-  A @{syntax_ref var} or @{syntax_ref typevar} describes an unknown, which is
-  internally a pair of base name and index (ML type @{ML_type indexname}).
-  These components are either separated by a dot as in \<open>?x.1\<close> or \<open>?x7.3\<close> or
-  run together as in \<open>?x1\<close>. The latter form is possible if the base name does
-  not end with digits. If the index is 0, it may be dropped altogether: \<open>?x\<close>
-  and \<open>?x0\<close> and \<open>?x.0\<close> all refer to the same unknown, with basename \<open>x\<close> and
-  index 0.
+  A @{syntax_ref term_var} or @{syntax_ref type_var} describes an unknown,
+  which is internally a pair of base name and index (ML type @{ML_type
+  indexname}). These components are either separated by a dot as in \<open>?x.1\<close> or
+  \<open>?x7.3\<close> or run together as in \<open>?x1\<close>. The latter form is possible if the base
+  name does not end with digits. If the index is 0, it may be dropped
+  altogether: \<open>?x\<close> and \<open>?x0\<close> and \<open>?x.0\<close> all refer to the same unknown, with
+  basename \<open>x\<close> and index 0.
 
   The syntax of @{syntax_ref string} admits any characters, including
   newlines; ``\<^verbatim>\<open>"\<close>'' (double-quote) and ``\<^verbatim>\<open>\\<close>'' (backslash) need to be
   escaped by a backslash; arbitrary character codes may be specified as
   ``\<^verbatim>\<open>\\<close>\<open>ddd\<close>'', with three decimal digits. Alternative strings according to

   Entity @{syntax name} usually refers to any name of types, constants,
   theorems etc.\ Quoted strings provide an escape for non-identifier names or
   those ruled out by outer syntax keywords (e.g.\ quoted \<^verbatim>\<open>"let"\<close>).
 
   @{rail \<open>
-    @{syntax_def name}: @{syntax ident} | @{syntax longident} |
-      @{syntax symident} | @{syntax nat} | @{syntax string}
+    @{syntax_def name}: @{syntax short_ident} | @{syntax long_ident} |
+      @{syntax sym_ident} | @{syntax nat} | @{syntax string}
     ;
     @{syntax_def par_name}: '(' @{syntax name} ')'
   \<close>}
 \<close>
 

   plain identifiers in the outer language may be used as inner language
   content without delimiters.
 
   @{rail \<open>
     @{syntax_def embedded}: @{syntax cartouche} | @{syntax string} |
-      @{syntax ident} | @{syntax longident} | @{syntax symident} |
-      @{syntax var} | @{syntax typefree} | @{syntax typevar} | @{syntax nat}
+      @{syntax short_ident} | @{syntax long_ident} | @{syntax sym_ident} |
+      @{syntax term_var} | @{syntax type_ident} | @{syntax type_var} | @{syntax nat}
   \<close>}
 \<close>
 
 
 subsection \<open>Comments \label{sec:comments}\<close>

   @{rail \<open>
     @{syntax_def named_inst}: variable '=' (type | term)
     ;
     @{syntax_def named_insts}: (named_inst @'and' +)
     ;
-    variable: @{syntax name} | @{syntax var} | @{syntax typefree} | @{syntax typevar}
+    variable: @{syntax name} | @{syntax term_var} | @{syntax type_ident} | @{syntax type_var}
   \<close>}
 
   Type declarations and definitions usually refer to @{syntax typespec} on the
   left-hand side. This models basic type constructor application at the outer
   syntax level. Note that only plain postfix notation is available here, but
   no infixes.
 
   @{rail \<open>
     @{syntax_def typespec}:
-      (() | @{syntax typefree} | '(' ( @{syntax typefree} + ',' ) ')') @{syntax name}
+      (() | @{syntax type_ident} | '(' ( @{syntax type_ident} + ',' ) ')') @{syntax name}
     ;
     @{syntax_def typespec_sorts}:
-      (() | (@{syntax typefree} ('::' @{syntax sort})?) |
-        '(' ( (@{syntax typefree} ('::' @{syntax sort})?) + ',' ) ')') @{syntax name}
+      (() | (@{syntax type_ident} ('::' @{syntax sort})?) |
+        '(' ( (@{syntax type_ident} ('::' @{syntax sort})?) + ',' ) ')') @{syntax name}
   \<close>}
 \<close>
 
 
 subsection \<open>Term patterns and declarations \label{sec:term-decls}\<close>

   Attributes have their own ``semi-inner'' syntax, in the sense that input
   conforming to @{syntax args} below is parsed by the attribute a second time.
   The attribute argument specifications may be any sequence of atomic entities
   (identifiers, strings etc.), or properly bracketed argument lists. Below
   @{syntax atom} refers to any atomic entity, including any @{syntax keyword}
-  conforming to @{syntax symident}.
-
-  @{rail \<open>
-    @{syntax_def atom}: @{syntax name} | @{syntax typefree} |
-      @{syntax typevar} | @{syntax var} | @{syntax nat} | @{syntax float} |
+  conforming to @{syntax sym_ident}.
+
+  @{rail \<open>
+    @{syntax_def atom}: @{syntax name} | @{syntax type_ident} |
+      @{syntax type_var} | @{syntax term_var} | @{syntax nat} | @{syntax float} |
       @{syntax keyword} | @{syntax cartouche}
     ;
     arg: @{syntax atom} | '(' @{syntax args} ')' | '[' @{syntax args} ']'
     ;
     @{syntax_def args}: arg *