address ubuntu warning and add shortcuts for maxsat

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

src/api/python/z3/z3.py

@@ -7548,11 +7548,11 @@ def Sum(*args):
     a__0 + a__1 + a__2 + a__3 + a__4
     """
     args  = _get_args(args)
-    if __debug__:
-        _z3_assert(len(args) > 0, "Non empty list of arguments expected")
+    if len(args) == 0:
+        return 0
     ctx   = _ctx_from_ast_arg_list(args)
-    if __debug__:
-        _z3_assert(ctx is not None, "At least one of the arguments must be a Z3 expression")
+    if ctx is None:
+        return _reduce(lambda a, b: a + b, args, 0)
     args  = _coerce_expr_list(args, ctx)
     if is_bv(args[0]):
         return _reduce(lambda a, b: a + b, args, 0)
@@ -7560,6 +7560,7 @@ def Sum(*args):
         _args, sz = _to_ast_array(args)
         return ArithRef(Z3_mk_add(ctx.ref(), sz, _args), ctx)
 
+
 def Product(*args):
     """Create the product of the Z3 expressions.
 
@@ -7573,11 +7574,11 @@ def Product(*args):
     a__0*a__1*a__2*a__3*a__4
     """
     args  = _get_args(args)
-    if __debug__:
-        _z3_assert(len(args) > 0, "Non empty list of arguments expected")
+    if len(args) == 0:
+        return 1
     ctx   = _ctx_from_ast_arg_list(args)
-    if __debug__:
-        _z3_assert(ctx is not None, "At least one of the arguments must be a Z3 expression")
+    if ctx is None:
+        return _reduce(lambda a, b: a * b, args, 1)    
     args  = _coerce_expr_list(args, ctx)
     if is_bv(args[0]):
         return _reduce(lambda a, b: a * b, args, 1)

src/ast/rewriter/bv_bounds.cpp

@@ -92,7 +92,7 @@ bool bv_bounds::is_uleq(expr * e, expr * & v, numeral & c) {
     expr * const ulel0 = to_app(ulel)->get_arg(0);
     if (ulel0 != eql0) return false;
     if ((m_bv_util.get_extract_high(ulel) + 1) != m_bv_util.get_extract_low(eql)) return false;
-    if (!m_bv_util.get_extract_low(ulel) == 0) return false;
+    if (m_bv_util.get_extract_low(ulel) != 0) return false;
     if (!m_bv_util.is_numeral(uler, uleqr_val, uleqr_sz)) return false;
     SASSERT(m_bv_util.get_bv_size(ulel0) == uleqr_sz + eqr_sz);
     v = ulel0;

src/opt/maxsmt.cpp

@@ -267,8 +267,10 @@ namespace opt {
 
     void maxsmt::display_answer(std::ostream& out) const {
         for (unsigned i = 0; i < m_soft_constraints.size(); ++i) {
-            out << mk_pp(m_soft_constraints[i], m)
-                << (get_assignment(i)?" |-> true\n":" |-> false\n");
+            expr* e = m_soft_constraints[i];
+            bool is_not = m.is_not(e, e);
+            out << mk_pp(e, m)
+                << ((is_not != get_assignment(i))?" |-> true\n":" |-> false\n");
         }
     }
     

src/tactic/arith/card2bv_tactic.cpp

@@ -116,6 +116,9 @@ namespace pb {
                 result = m.mk_and(sz, args);
                 return BR_DONE;
             }
+            if (is_atmost1(f, sz, args, result)) {
+                return BR_DONE;
+            }
             br_status st = mk_shannon(f, sz, args, result);
             if (st == BR_FAILED) {
                 mk_bv(f, sz, args, result);
@@ -165,6 +168,43 @@ namespace pb {
             return BR_FAILED;
     }
 
+    expr_ref card2bv_rewriter::mk_atmost1(unsigned sz, expr * const* args) {
+        expr_ref f1(m), f2(m), f3(m), result(m);
+        f1 = bv.mk_bv(sz, args);
+        f2 = bv.mk_bv_sub(f1, bv.mk_numeral(rational(1), sz));
+        f3 = m.mk_app(bv.get_fid(), OP_BAND, f1, f2);
+        result = m.mk_eq(f3, bv.mk_numeral(rational(0), sz));
+        return result;
+    }
+
+    bool card2bv_rewriter::is_atmost1(func_decl* f, unsigned sz, expr * const* args, expr_ref& result) {
+        switch (f->get_decl_kind()) {
+        case OP_AT_MOST_K:            
+        case OP_PB_LE: 
+            if (pb.get_k(f).is_one() && pb.has_unit_coefficients(f)) {
+                result = mk_atmost1(sz, args);
+                return true;
+            }
+            return false;
+        case OP_AT_LEAST_K:
+        case OP_PB_GE: 
+            if (pb.get_k(f) == rational(sz-1) && pb.has_unit_coefficients(f)) {
+                expr_ref_vector nargs(m);
+                for (unsigned i = 0; i < sz; ++i) {
+                    nargs.push_back(mk_not(args[i]));
+                }
+                result = mk_atmost1(nargs.size(), nargs.c_ptr());
+                return true;
+            }
+            return false;
+        case OP_PB_EQ:
+            return false;
+        default:
+            UNREACHABLE();
+            return false;
+        }        
+    }
+
     bool card2bv_rewriter::is_or(func_decl* f) {
         switch (f->get_decl_kind()) {
         case OP_AT_MOST_K:

src/tactic/arith/card2bv_tactic.h

@@ -52,6 +52,8 @@ namespace pb {
         expr* mk_ite(expr* c, expr* hi, expr* lo);
         bool is_or(func_decl* f);
         bool is_and(func_decl* f);
+        bool is_atmost1(func_decl* f, unsigned sz, expr * const* args, expr_ref& result);
+        expr_ref mk_atmost1(unsigned sz, expr * const* args);
 
     public:
         card2bv_rewriter(ast_manager& m);

src/tactic/bv/bv_bound_chk_tactic.cpp

@@ -71,7 +71,6 @@ struct bv_bound_chk_rewriter_cfg : public default_rewriter_cfg {
         result_pr = 0;
         const family_id fid = f->get_family_id();
         if (fid != m_b_rw.get_fid()) return BR_FAILED;
-        const decl_kind k = f->get_decl_kind();
         bv_bounds bvb(m());
         const br_status rv = bvb.rewrite(m_bv_ineq_consistency_test_max, f, num, args, result);
         if (rv != BR_FAILED && (m_m.is_false(result) || m_m.is_true(result))) m_stats.m_unsats++;