to_mbp_benchmark(): prints an mbp problem in benchmark format

currently unused. See comment in spacer_util.c:qe_project for example
usage

src/muz/spacer/spacer_util.cpp

@@ -469,6 +469,24 @@ namespace spacer {
         sub (fml);
     }
 
+void to_mbp_benchmark(std::ostream &out, expr* fml, const app_ref_vector &vars) {
+    ast_manager &m = vars.m();
+    ast_pp_util pp(m);
+    pp.collect(fml);
+    pp.display_decls(out);
+
+    out << "(define-fun mbp_benchmark_fml () Bool\n  ";
+    out << mk_pp(fml, m) << ")\n\n";
+
+    out << "(push)\n"
+        << "(assert mbp_benchmark_fml)\n"
+        << "(check-sat)\n"
+        << "(mbp mbp_benchmark_fml (";
+    for (auto v : vars) {out << mk_pp(v, m) << " ";}
+    out << "))\n"
+        << "(pop)\n"
+        << "(exit)\n";
+}
     /*
      * eliminate simple equalities using qe_lite
      * then, MBP for Booleans (substitute), reals (based on LW), ints (based on Cooper), and arrays
@@ -489,6 +507,10 @@ namespace spacer {
             fml = mk_and(flat);
         }
 
+
+        // uncomment for benchmarks
+        //to_mbp_benchmark(verbose_stream(), fml, vars);
+
         app_ref_vector arith_vars (m);
         app_ref_vector array_vars (m);
         array_util arr_u (m);

src/muz/spacer/spacer_util.h

@@ -125,6 +125,9 @@ bool is_difference_logic(ast_manager& m, unsigned num_fmls, expr* const* fmls);
 
 bool is_utvpi_logic(ast_manager& m, unsigned num_fmls, expr* const* fmls);
 
+void to_mbp_benchmark(std::ostream &out, const expr* fml,
+                      const app_ref_vector &vars);
+
 /**
  * do the following in sequence
  * 1. use qe_lite to cheaply eliminate vars