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);
}
}
}
/**
\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);
}
}