write_dimacs_sat_file writes outer parentheses again

--- a/src/HOL/Tools/sat_solver.ML	Tue Jul 26 12:23:10 2005 +0200
+++ b/src/HOL/Tools/sat_solver.ML	Tue Jul 26 12:40:52 2005 +0200
@@ -177,7 +177,7 @@
 				"c This file was generated by SatSolver.write_dimacs_sat_file\n" ^
 				"c (c) Tjark Weber\n" ^
 				"p sat " ^ string_of_int number_of_vars ^ "\n" ^
-				(*"(" ^*) sat_string fm ^ "\n" (*")\n"*)
+				"(" ^ sat_string fm ^ ")\n"
 			end)
 	end;