working on hitting sets

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/muz/base/dl_context.h

@@ -278,6 +278,12 @@ namespace datalog {
 
         void register_variable(func_decl* var);
 
+        /*
+          Replace constants that have been registered as 
+          variables by de-Bruijn indices and corresponding
+          universal (if is_forall is true) or existential 
+          quantifier.
+         */
         expr_ref bind_variables(expr* fml, bool is_forall);
 
         /**

src/muz/base/fixedpoint_params.pyg

@@ -77,6 +77,7 @@ def_module_params('fixedpoint',
 			  ('mbqi', BOOL, True, 'DUALITY: use model-based quantifier instantion'),
 			  ('batch_expand', BOOL, False, 'DUALITY: use batch expansion'),
                           ('dump_aig', SYMBOL, '', 'Dump clauses in AIG text format (AAG) to the given file name'),
+			  ('conjecture_file', STRING, '', 'DUALITY: save conjectures to file'),
                           ))