Beispiel #1
0
 void process(expr * f) {
     if (fvisited.is_marked(f))
         return;
     fvisited.mark(f);
     todo.push_back(f);
     while (!todo.empty()) {
         expr * t = todo.back();
         todo.pop_back();
         if (is_uninterp_const(t))
             continue;
         if (is_app(t) && to_app(t)->get_family_id() == m.get_basic_family_id() && to_app(t)->get_num_args() > 0) {
             decl_kind k = to_app(t)->get_decl_kind();
             if (k == OP_OR || k == OP_NOT || k == OP_IFF || ((k == OP_EQ || k == OP_ITE) && m.is_bool(to_app(t)->get_arg(1)))) {
                 unsigned num = to_app(t)->get_num_args();
                 for (unsigned i = 0; i < num; i++) {
                     expr * arg = to_app(t)->get_arg(i);
                     if (fvisited.is_marked(arg))
                         continue;
                     fvisited.mark(arg);
                     todo.push_back(arg);
                 }
             }
         }
         else {
             quick_for_each_expr(proc, tvisited, t);
         }
     }
 }
Beispiel #2
0
/**
   \brief Auxiliary method for local_ctx_simp.

   Replace args[i] by true if marked in neg_lits.
   Replace args[i] by false if marked in pos_lits.
*/
bool bool_rewriter::simp_nested_not_or(unsigned num_args, expr * const * args,
                                       expr_fast_mark1 & neg_lits, expr_fast_mark2 & pos_lits, expr_ref & result) {
    ptr_buffer<expr> new_args;
    bool simp = false;
    m_local_ctx_cost += num_args;
    for (unsigned i = 0; i < num_args; i++) {
        expr * arg = args[i];
        if (neg_lits.is_marked(arg)) {
            result = m().mk_false();
            return true;
        }
        if (pos_lits.is_marked(arg)) {
            simp = true;
            continue;
        }
        if (m().is_not(arg)) {
            expr * atom = to_app(arg)->get_arg(0);
            if (neg_lits.is_marked(atom)) {
                simp = true;
                continue;
            }
            if (pos_lits.is_marked(atom)) {
                result = m().mk_false();
                return true;
            }
        }
        new_args.push_back(arg);
    }
    if (simp) {
        switch(new_args.size()) {
        case 0:
            result = m().mk_true();
            return true;
        case 1:
            mk_not(new_args[0], result);
            return true;
        default:
            result = m().mk_not(m().mk_or(new_args.size(), new_args.c_ptr()));
            return true;
        }
    }
    return false;
}
 /**
    \brief Unmark atoms that occur in the boolean structure.
 */
 void formula_compiler::unmark_nested_atoms(assertion_set const & s, expr_fast_mark2 & axioms) {
     ast_manager & m = s.m();
     expr_fast_mark1 visited;
     unmark_axioms_proc proc(axioms);
     unsigned sz = s.size();
     for (unsigned i = 0; i < sz; i++) {
         expr * f = s.form(i);
         while (m.is_not(f, f));
         if (axioms.is_marked(f))
             continue;
         quick_for_each_expr(proc, visited, f);
     }
 }