From 2a745d5224c416ce81bcf8f5d586cdc24a879d1e Mon Sep 17 00:00:00 2001 From: Nikolaj Bjorner Date: Wed, 3 Apr 2013 14:46:58 -0700 Subject: [PATCH] adding model convertion to quantifier transformation Signed-off-by: Nikolaj Bjorner --- src/api/api_datalog.cpp | 4 +- src/muz_qe/datalog_parser.cpp | 4 +- src/muz_qe/dl_cmds.cpp | 1 + src/muz_qe/dl_context.cpp | 11 +- src/muz_qe/dl_context.h | 14 +- src/muz_qe/dl_mk_karr_invariants.cpp | 2 +- src/muz_qe/dl_mk_loop_counter.cpp | 4 +- src/muz_qe/dl_mk_quantifier_abstraction.cpp | 160 ++++++++++++++++-- src/muz_qe/dl_mk_quantifier_abstraction.h | 5 +- src/muz_qe/dl_mk_quantifier_instantiation.cpp | 38 ++--- src/muz_qe/dl_mk_quantifier_instantiation.h | 1 - src/muz_qe/dl_rule.cpp | 2 +- src/muz_qe/horn_tactic.cpp | 2 +- 13 files changed, 188 insertions(+), 60 deletions(-) diff --git a/src/api/api_datalog.cpp b/src/api/api_datalog.cpp index 0f100e747..f6eadfea0 100644 --- a/src/api/api_datalog.cpp +++ b/src/api/api_datalog.cpp @@ -358,7 +358,7 @@ extern "C" { v->m_ast_vector.push_back(coll.m_queries[i].get()); } for (unsigned i = 0; i < coll.m_rels.size(); ++i) { - to_fixedpoint_ref(d)->ctx().register_predicate(coll.m_rels[i].get()); + to_fixedpoint_ref(d)->ctx().register_predicate(coll.m_rels[i].get(), true); } for (unsigned i = 0; i < coll.m_rules.size(); ++i) { to_fixedpoint_ref(d)->add_rule(coll.m_rules[i].get(), coll.m_names[i]); @@ -415,7 +415,7 @@ extern "C" { void Z3_API Z3_fixedpoint_register_relation(Z3_context c,Z3_fixedpoint d, Z3_func_decl f) { Z3_TRY; LOG_Z3_fixedpoint_register_relation(c, d, f); - to_fixedpoint_ref(d)->ctx().register_predicate(to_func_decl(f)); + to_fixedpoint_ref(d)->ctx().register_predicate(to_func_decl(f), true); Z3_CATCH; } diff --git a/src/muz_qe/datalog_parser.cpp b/src/muz_qe/datalog_parser.cpp index cfe283410..545f3e14a 100644 --- a/src/muz_qe/datalog_parser.cpp +++ b/src/muz_qe/datalog_parser.cpp @@ -441,6 +441,7 @@ protected: unsigned m_sym_idx; std::string m_path; str2sort m_sort_dict; + // true if an error occured during the current call to the parse_stream // function @@ -812,7 +813,8 @@ protected: } f = m_manager.mk_func_decl(s, domain.size(), domain.c_ptr(), m_manager.mk_bool_sort()); - m_context.register_predicate(f); + m_context.register_predicate(f, true); + while (tok == TK_ID) { char const* pred_pragma = m_lexer->get_token_data(); if(strcmp(pred_pragma, "printtuples")==0 || strcmp(pred_pragma, "outputtuples")==0) { diff --git a/src/muz_qe/dl_cmds.cpp b/src/muz_qe/dl_cmds.cpp index aef14e051..c1e3f85f9 100644 --- a/src/muz_qe/dl_cmds.cpp +++ b/src/muz_qe/dl_cmds.cpp @@ -229,6 +229,7 @@ public: status = dlctx.query(m_target); } catch (z3_error & ex) { + ctx.regular_stream() << "(error \"query failed: " << ex.msg() << "\")" << std::endl; throw ex; } catch (z3_exception& ex) { diff --git a/src/muz_qe/dl_context.cpp b/src/muz_qe/dl_context.cpp index 44852a52f..a928d7ba7 100644 --- a/src/muz_qe/dl_context.cpp +++ b/src/muz_qe/dl_context.cpp @@ -302,14 +302,6 @@ namespace datalog { return m_preds.contains(pred); } - func_decl * context::try_get_predicate_decl(symbol pred_name) const { - func_decl * res; - if (!m_preds_by_name.find(pred_name, res)) { - return 0; - } - return res; - } - void context::register_variable(func_decl* var) { m_vars.push_back(m.mk_const(var)); } @@ -361,7 +353,6 @@ namespace datalog { m_pinned.push_back(decl); m_preds.insert(decl); if (named) { - SASSERT(!m_preds_by_name.contains(decl->get_name())); m_preds_by_name.insert(decl->get_name(), decl); } } @@ -448,7 +439,7 @@ namespace datalog { func_decl* new_pred = m.mk_fresh_func_decl(prefix, suffix, arity, domain, m.mk_bool_sort()); - register_predicate(new_pred); + register_predicate(new_pred, true); if (m_rel.get()) { m_rel->inherit_predicate_kind(new_pred, orig_pred); diff --git a/src/muz_qe/dl_context.h b/src/muz_qe/dl_context.h index 0c4558a28..cb432d4e9 100644 --- a/src/muz_qe/dl_context.h +++ b/src/muz_qe/dl_context.h @@ -183,18 +183,22 @@ namespace datalog { retrieved by the try_get_predicate_decl() function. Auxiliary predicates introduced e.g. by rule transformations do not need to be named. */ - void register_predicate(func_decl * pred, bool named = true); + void register_predicate(func_decl * pred, bool named); bool is_predicate(func_decl * pred) const; - + /** \brief If a predicate name has a \c func_decl object assigned, return pointer to it; otherwise return 0. - + Not all \c func_decl object used as relation identifiers need to be assigned to their names. Generally, the names coming from the parses are registered here. - */ - func_decl * try_get_predicate_decl(symbol pred_name) const; + */ + func_decl * try_get_predicate_decl(symbol const& pred_name) const { + func_decl * res = 0; + m_preds_by_name.find(pred_name, res); + return res; + } /** \brief Create a fresh head predicate declaration. diff --git a/src/muz_qe/dl_mk_karr_invariants.cpp b/src/muz_qe/dl_mk_karr_invariants.cpp index 2596a7337..7932735fe 100644 --- a/src/muz_qe/dl_mk_karr_invariants.cpp +++ b/src/muz_qe/dl_mk_karr_invariants.cpp @@ -206,7 +206,7 @@ namespace datalog { for (; it != end; ++it) { rule_ref r(*it, m_inner_ctx.get_rule_manager()); m_inner_ctx.add_rule(r); - m_inner_ctx.register_predicate(r->get_decl()); + m_inner_ctx.register_predicate(r->get_decl(), false); } m_inner_ctx.close(); rule_set::decl2rules::iterator dit = source.begin_grouped_rules(); diff --git a/src/muz_qe/dl_mk_loop_counter.cpp b/src/muz_qe/dl_mk_loop_counter.cpp index 172198746..6b95671f2 100644 --- a/src/muz_qe/dl_mk_loop_counter.cpp +++ b/src/muz_qe/dl_mk_loop_counter.cpp @@ -72,14 +72,14 @@ namespace datalog { for (unsigned j = 0; j < utsz; ++j, ++cnt) { tail.push_back(add_arg(r.get_tail(j), cnt)); neg.push_back(r.is_neg_tail(j)); - ctx.register_predicate(tail.back()->get_decl()); + ctx.register_predicate(tail.back()->get_decl(), false); } for (unsigned j = utsz; j < tsz; ++j) { tail.push_back(r.get_tail(j)); neg.push_back(false); } head = add_arg(r.get_head(), cnt); - ctx.register_predicate(head->get_decl()); + ctx.register_predicate(head->get_decl(), false); // set the loop counter to be an increment of the previous bool found = false; unsigned last = head->get_num_args()-1; diff --git a/src/muz_qe/dl_mk_quantifier_abstraction.cpp b/src/muz_qe/dl_mk_quantifier_abstraction.cpp index 511ab7b9a..0dd48ef53 100644 --- a/src/muz_qe/dl_mk_quantifier_abstraction.cpp +++ b/src/muz_qe/dl_mk_quantifier_abstraction.cpp @@ -21,9 +21,110 @@ Revision History: #include "dl_mk_quantifier_abstraction.h" #include "dl_context.h" +#include "expr_safe_replace.h" +#include "expr_abstract.h" namespace datalog { + + // model converter: + // Given model for P^(x, y, i, a[i]) + // create model: P(x,y,a) == forall i . P^(x,y,i,a[i]) + // requires substitution and list of bound variables. + + class mk_quantifier_abstraction::qa_model_converter : public model_converter { + ast_manager& m; + func_decl_ref_vector m_old_funcs; + func_decl_ref_vector m_new_funcs; + vector m_subst; + vector > m_bound; + + public: + + qa_model_converter(ast_manager& m): + m(m), m_old_funcs(m), m_new_funcs(m) {} + + virtual ~qa_model_converter() {} + + virtual model_converter * translate(ast_translation & translator) { + return alloc(qa_model_converter, m); + } + + void insert(func_decl* old_p, func_decl* new_p, expr_ref_vector& sub, svector const& bound) { + m_old_funcs.push_back(old_p); + m_new_funcs.push_back(new_p); + m_subst.push_back(sub); + m_bound.push_back(bound); + } + + virtual void operator()(model_ref & model) { + for (unsigned i = 0; i < m_new_funcs.size(); ++i) { + func_decl* p = m_new_funcs[i].get(); + func_decl* q = m_old_funcs[i].get(); + expr_ref_vector const& s = m_subst[i]; + svector const& is_bound = m_bound[i]; + func_interp* f = model->get_func_interp(p); + expr_ref body(m); + unsigned arity_p = p->get_arity(); + unsigned arity_q = q->get_arity(); + SASSERT(0 < arity_p); + model->register_decl(p, f); + func_interp* g = alloc(func_interp, m, arity_q); + + if (f) { + body = f->get_interp(); + SASSERT(!f->is_partial()); + SASSERT(body); + } + else { + body = m.mk_false(); + } + // TBD. create quantifier wrapper around body. + + // 1. replace variables by the compound terms from + // the original predicate. + expr_safe_replace sub(m); + for (unsigned i = 0; i < s.size(); ++i) { + sub.insert(m.mk_var(i, m.get_sort(s[i])), s[i]); + } + sub(body); + sub.reset(); + + // 2. replace bound variables by constants. + expr_ref_vector consts(m), bound(m), free(m); + ptr_vector sorts; + svector names; + for (unsigned i = 0; i < q->get_arity(); ++i) { + sort* s = q->get_domain(i); + consts.push_back(m.mk_fresh_const("C", s)); + sub.insert(m.mk_var(i, s), consts.back()); + if (is_bound[i]) { + bound.push_back(consts.back()); + names.push_back(symbol(i)); + sorts.push_back(s); + } + else { + free.push_back(consts.back()); + } + } + sub(body); + sub.reset(); + + // 3. abstract and quantify those variables that should be bound. + expr_abstract(m, 0, bound.size(), bound.c_ptr(), body, body); + body = m.mk_forall(names.size(), sorts.c_ptr(), names.c_ptr(), body); + + // 4. replace remaining constants by variables. + for (unsigned i = 0; i < free.size(); ++i) { + sub.insert(free[i].get(), m.mk_var(i, m.get_sort(free[i].get()))); + } + sub(body); + g->set_else(body); + model->register_decl(q, g); + } + } + }; + mk_quantifier_abstraction::mk_quantifier_abstraction( context & ctx, unsigned priority): plugin(priority), @@ -33,8 +134,7 @@ namespace datalog { m_refs(m) { } - mk_quantifier_abstraction::~mk_quantifier_abstraction() { - + mk_quantifier_abstraction::~mk_quantifier_abstraction() { } func_decl* mk_quantifier_abstraction::declare_pred(func_decl* old_p) { @@ -52,22 +152,41 @@ namespace datalog { func_decl* new_p = 0; if (!m_old2new.find(old_p, new_p)) { + expr_ref_vector sub(m); + svector bound; sort_ref_vector domain(m); + expr_ref arg(m); for (unsigned i = 0; i < sz; ++i) { sort* s = old_p->get_domain(i); + unsigned lookahead = 0; + sort* s0 = s; + while (a.is_array(s0)) { + lookahead += get_array_arity(s0); + s0 = get_array_range(s0); + } + arg = m.mk_var(bound.size() + lookahead, s); while (a.is_array(s)) { unsigned arity = get_array_arity(s); + expr_ref_vector args(m); for (unsigned j = 0; j < arity; ++j) { domain.push_back(get_array_domain(s, j)); + args.push_back(m.mk_var(bound.size(), domain.back())); + bound.push_back(true); } + arg = mk_select(arg, args.size(), args.c_ptr()); s = get_array_range(s); } domain.push_back(s); + bound.push_back(false); + sub.push_back(arg); } SASSERT(old_p->get_range() == m.mk_bool_sort()); new_p = m.mk_func_decl(old_p->get_name(), domain.size(), domain.c_ptr(), old_p->get_range()); m_refs.push_back(new_p); - m_ctx.register_predicate(new_p); + m_ctx.register_predicate(new_p, false); + if (m_mc) { + m_mc->insert(old_p, new_p, sub, bound); + } } return new_p; } @@ -88,10 +207,7 @@ namespace datalog { for (unsigned j = 0; j < arity; ++j) { args.push_back(m.mk_var(idx++, get_array_domain(s, j))); } - ptr_vector args2; - args2.push_back(arg); - args2.append(arity, args.c_ptr()-arity); - arg = a.mk_select(args2.size(), args2.c_ptr()); + arg = mk_select(arg, arity, args.c_ptr()+args.size()-arity); s = get_array_range(s); } args.push_back(arg); @@ -130,10 +246,7 @@ namespace datalog { names.push_back(symbol(idx)); args.push_back(m.mk_var(idx++, vars.back())); } - ptr_vector args2; - args2.push_back(arg); - args2.append(arity, args.c_ptr()-arity); - arg = a.mk_select(args2.size(), args2.c_ptr()); + arg = mk_select(arg, arity, args.c_ptr()+args.size()-arity); s = get_array_range(s); } if (is_pattern) { @@ -151,8 +264,16 @@ namespace datalog { result = m.mk_eq(m.mk_forall(vars.size(), vars.c_ptr(), names.c_ptr(), result, 1, qid, skid, 1, &pat), m.mk_true()); return result; } + + expr * mk_quantifier_abstraction::mk_select(expr* arg, unsigned num_args, expr* const* args) { + ptr_vector args2; + args2.push_back(arg); + args2.append(num_args, args); + return a.mk_select(args2.size(), args2.c_ptr()); + } rule_set * mk_quantifier_abstraction::operator()(rule_set const & source) { + TRACE("dl", tout << "quantify " << source.get_num_rules() << " " << m_ctx.get_params().quantify_arrays() << "\n";); if (!m_ctx.get_params().quantify_arrays()) { return 0; } @@ -168,6 +289,10 @@ namespace datalog { svector neg; rule_counter& vc = rm.get_counter(); + if (m_ctx.get_model_converter()) { + m_mc = alloc(qa_model_converter, m); + } + for (unsigned i = 0; i < sz; ++i) { tail.reset(); neg.reset(); @@ -186,17 +311,22 @@ namespace datalog { head = mk_head(r.get_head(), cnt); new_rule = rm.mk(head, tail.size(), tail.c_ptr(), neg.c_ptr(), r.name(), true); + TRACE("dl", r.display(m_ctx, tout); new_rule->display(m_ctx, tout);); result->add_rule(new_rule); - } - - // model converter: TBD. - // proof converter: TBD. + + // proof converter: proofs are not necessarily preserved using this transformation. if (m_old2new.empty()) { dealloc(result); + dealloc(m_mc); result = 0; } + else { + m_ctx.add_model_converter(m_mc); + } + m_mc = 0; + return result; } diff --git a/src/muz_qe/dl_mk_quantifier_abstraction.h b/src/muz_qe/dl_mk_quantifier_abstraction.h index 8c26e277a..c7e6c6bb4 100644 --- a/src/muz_qe/dl_mk_quantifier_abstraction.h +++ b/src/muz_qe/dl_mk_quantifier_abstraction.h @@ -34,16 +34,19 @@ namespace datalog { class context; class mk_quantifier_abstraction : public rule_transformer::plugin { + class qa_model_converter; ast_manager& m; context& m_ctx; array_util a; - func_decl_ref_vector m_refs; + func_decl_ref_vector m_refs; obj_map m_new2old; obj_map m_old2new; + qa_model_converter* m_mc; func_decl* declare_pred(func_decl* old_p); app_ref mk_head(app* p, unsigned idx); app_ref mk_tail(app* p); + expr* mk_select(expr* a, unsigned num_args, expr* const* args); public: mk_quantifier_abstraction(context & ctx, unsigned priority); diff --git a/src/muz_qe/dl_mk_quantifier_instantiation.cpp b/src/muz_qe/dl_mk_quantifier_instantiation.cpp index 11c039bf8..993e5ada5 100644 --- a/src/muz_qe/dl_mk_quantifier_instantiation.cpp +++ b/src/muz_qe/dl_mk_quantifier_instantiation.cpp @@ -46,8 +46,7 @@ namespace datalog { qs.reset(); unsigned tsz = r.get_tail_size(); for (unsigned j = 0; j < tsz; ++j) { - conjs.push_back(r.get_tail(j)); - + conjs.push_back(r.get_tail(j)); } datalog::flatten_and(conjs); for (unsigned j = 0; j < conjs.size(); ++j) { @@ -98,17 +97,12 @@ namespace datalog { expr* t = todo[j].second; if (is_var(p)) { unsigned idx = to_var(p)->get_idx(); - expr* t2 = m_binding[idx]; - if (!t2) { + if (!m_binding[idx]) { m_binding[idx] = t; match(i, pat, j + 1, todo, q, conjs); m_binding[idx] = 0; return; } - else if (m_uf.find(t2->get_id()) != m_uf.find(t->get_id())) { - // matching failed. - return; - } ++j; continue; } @@ -168,12 +162,6 @@ namespace datalog { TRACE("dl", tout << mk_pp(q, m) << "\n==>\n" << mk_pp(res, m) << "\n";); } - void mk_quantifier_instantiation::merge(expr* e1, expr* e2) { - unsigned i1 = e1->get_id(); - unsigned i2 = e2->get_id(); - m_uf.merge(i1, i2); - } - void mk_quantifier_instantiation::collect_egraph(expr* e) { expr* e1, *e2; m_todo.push_back(e); @@ -186,12 +174,12 @@ namespace datalog { } unsigned n = e->get_id(); if (n >= m_terms.size()) { - m_terms.resize(e->get_id()+1); + m_terms.resize(n+1); } - m_terms[e->get_id()] = e; + m_terms[n] = e; visited.mark(e); if (m.is_eq(e, e1, e2) || m.is_iff(e, e1, e2)) { - merge(e1, e2); + m_uf.merge(e1->get_id(), e2->get_id()); } if (is_app(e)) { app* ap = to_app(e); @@ -246,12 +234,23 @@ namespace datalog { TRACE("dl", r.display(m_ctx, tout); tout << mk_pp(fml, m) << "\n";); rule_ref_vector added_rules(rm); - proof_ref pr(m); // proofs are TBD. + proof_ref pr(m); rm.mk_rule(fml, pr, added_rules); + if (r.get_proof()) { + // use def-axiom to encode that new rule is a weakening of the original. + proof* p1 = r.get_proof(); + for (unsigned i = 0; i < added_rules.size(); ++i) { + rule* r2 = added_rules[i].get(); + r2->to_formula(fml); + pr = m.mk_modus_ponens(m.mk_def_axiom(m.mk_implies(m.get_fact(p1), fml)), p1); + r2->set_proof(m, pr); + } + } rules.add_rules(added_rules.size(), added_rules.c_ptr()); } rule_set * mk_quantifier_instantiation::operator()(rule_set const & source) { + TRACE("dl", tout << m_ctx.get_params().instantiate_quantifiers() << "\n";); if (!m_ctx.get_params().instantiate_quantifiers()) { return 0; } @@ -286,8 +285,7 @@ namespace datalog { } } - // model converter: TBD. - // proof converter: TBD. + // model convertion: identity function. if (!instantiated) { dealloc(result); diff --git a/src/muz_qe/dl_mk_quantifier_instantiation.h b/src/muz_qe/dl_mk_quantifier_instantiation.h index 969a0bf23..138d5abee 100644 --- a/src/muz_qe/dl_mk_quantifier_instantiation.h +++ b/src/muz_qe/dl_mk_quantifier_instantiation.h @@ -112,7 +112,6 @@ namespace datalog { obj_map*> m_funs; - void merge(expr* e1, expr* e2); void extract_quantifiers(rule& r, expr_ref_vector& conjs, quantifier_ref_vector& qs); void collect_egraph(expr* e); void instantiate_rule(rule& r, expr_ref_vector& conjs, quantifier_ref_vector& qs, rule_set& rules); diff --git a/src/muz_qe/dl_rule.cpp b/src/muz_qe/dl_rule.cpp index 14a316e48..b7d6d9fae 100644 --- a/src/muz_qe/dl_rule.cpp +++ b/src/muz_qe/dl_rule.cpp @@ -135,7 +135,7 @@ namespace datalog { h.set_name(name); h(fml, p, fmls, prs); for (unsigned i = 0; i < h.get_fresh_predicates().size(); ++i) { - m_ctx.register_predicate(h.get_fresh_predicates()[i]); + m_ctx.register_predicate(h.get_fresh_predicates()[i], false); } for (unsigned i = 0; i < fmls.size(); ++i) { mk_rule_core2(fmls[i].get(), prs[i].get(), rules, name); diff --git a/src/muz_qe/horn_tactic.cpp b/src/muz_qe/horn_tactic.cpp index 02c41c091..1a8f562d9 100644 --- a/src/muz_qe/horn_tactic.cpp +++ b/src/muz_qe/horn_tactic.cpp @@ -92,7 +92,7 @@ class horn_tactic : public tactic { void register_predicate(expr* a) { SASSERT(is_predicate(a)); - m_ctx.register_predicate(to_app(a)->get_decl(), true); + m_ctx.register_predicate(to_app(a)->get_decl(), false); } void check_predicate(ast_mark& mark, expr* a) {