better documentation regarding user-edition of PVS files

Makefile.in

@@ -1458,7 +1458,8 @@ doc/bnf: doc/bnf.mll
 	$(OCAMLOPT) -o $@ doc/bnf.ml
 
 DOC = api glossary ide intro library macros manpages install coq_tactic \
-      realizations manual starting syntax syntaxref technical version whyml
+      realizations manual starting syntax syntaxref technical version whyml \
+      pvs
 
 DOCTEX = $(addprefix doc/, $(addsuffix .tex, $(DOC)))
 

doc/pvs.tex

@@ -29,8 +29,10 @@ realization:
   \texttt{AXIOM} with either \texttt{LEMMA} or \texttt{THEOREM}.
 
 \item insert anything between generated declarations, such as a lemma,
-  an extra definition for the purpose of a proof, etc.
+  an extra definition for the purpose of a proof, an extra
+  \texttt{IMPORTING} command, etc. Do not forget to surround these
+  extra declarations with blank lines.
 \end{itemize}
-\why makes some effort to merge the new declarations with the old ones
-and with the user chunks. If it happens that some chunks could not be
+\why makes some effort to merge new declarations with old ones
+and with user chunks. If it happens that some chunks could not be
 merged, they are appended at the end of the file, in comments.

src/printer/pvs.ml

@@ -886,7 +886,9 @@ let print_task printer_args realize ?old fmt task =
        let lib = if path = thpath then "" else String.concat "." path ^ "@" in
        fprintf fmt "IMPORTING %s%s@\n" lib th.Theory.th_name.id_string)
     realized_theories;
-  fprintf fmt "%% do not edit above this line@\n@\n";
+  fprintf fmt "%% do not edit above this line@\n";
+  fprintf fmt
+    "%% surround new declarations you insert below with blank lines@\n@\n";
   print_decls ~old info fmt local_decls;
   output_remaining fmt !old;
   fprintf fmt "@]@\nEND %s@\n@]" thname