clarified signature;

--- a/src/Pure/Thy/latex.ML	Sat Nov 13 19:47:24 2021 +0100
+++ b/src/Pure/Thy/latex.ML	Sat Nov 13 20:12:34 2021 +0100
@@ -24,7 +24,6 @@
   val begin_tag: string -> string
   val end_tag: string -> string
   val environment_text: string -> text -> text
-  val environment: string -> string -> string
   val isabelle_body: string -> text -> text
   val theory_entry: string -> string
   val index_escape: string -> string
@@ -208,12 +207,10 @@
 
 (* theory presentation *)
 
-fun environment_delim name =
- ("%\n\\begin{" ^ output_name name ^ "}%\n",
-  "%\n\\end{" ^ output_name name ^ "}");
-
-fun environment_text name = environment_delim name |-> enclose_text;
-fun environment name = environment_delim name |-> enclose;
+fun environment_text name =
+  enclose_text
+    ("%\n\\begin{" ^ output_name name ^ "}%\n")
+    ("%\n\\end{" ^ output_name name ^ "}");
 
 fun isabelle_body name =
   enclose_text

--- a/src/Pure/Tools/rail.ML	Sat Nov 13 19:47:24 2021 +0100
+++ b/src/Pure/Tools/rail.ML	Sat Nov 13 20:12:34 2021 +0100
@@ -381,7 +381,7 @@
         output "" rail' ^
         "\\rail@end\n"
       end;
-  in Latex.string (Latex.environment "railoutput" (implode (map output_rule rules))) end;
+  in Latex.environment_text "railoutput" (Latex.string (implode (map output_rule rules))) end;
 
 val _ = Theory.setup
   (Document_Output.antiquotation_raw_embedded \<^binding>\<open>rail\<close> (Scan.lift Args.text_input)