586 lines
19 KiB
C++
586 lines
19 KiB
C++
/*
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Copyright (c) 2015 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Leonardo de Moura
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*/
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#include <algorithm>
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#include "kernel/instantiate.h"
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#include "kernel/abstract.h"
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#include "kernel/for_each_fn.h"
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#include "kernel/replace_fn.h"
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#include "library/replace_visitor.h"
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#include "library/blast/util.h"
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#include "library/blast/state.h"
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namespace lean {
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namespace blast {
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static name * g_prefix = nullptr;
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bool metavar_decl::restrict_context_using(metavar_decl const & other) {
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buffer<unsigned> to_erase;
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m_assumptions.for_each([&](unsigned hidx) {
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if (!other.contains_href(hidx))
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to_erase.push_back(hidx);
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});
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for (unsigned hidx : to_erase)
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m_assumptions.erase(hidx);
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return !to_erase.empty();
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}
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state::state() {}
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expr state::mk_metavar(hypothesis_idx_set const & c, expr const & type) {
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unsigned midx = mk_mref_idx();
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m_metavar_decls.insert(midx, metavar_decl(c, type));
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return blast::mk_mref(midx);
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}
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expr state::mk_metavar(hypothesis_idx_buffer const & b, expr const & type) {
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hypothesis_idx_set ctx;
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for (unsigned const & hidx : b)
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ctx.insert(hidx);
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return mk_metavar(ctx, type);
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}
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expr state::mk_metavar(expr const & type) {
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return state::mk_metavar(get_assumptions(), type);
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}
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void state::restrict_mref_context_using(expr const & mref1, expr const & mref2) {
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metavar_decl const * d1 = m_metavar_decls.find(mref_index(mref1));
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metavar_decl const * d2 = m_metavar_decls.find(mref_index(mref2));
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lean_assert(d1);
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lean_assert(d2);
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metavar_decl new_d1(*d1);
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if (new_d1.restrict_context_using(*d2))
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m_metavar_decls.insert(mref_index(mref1), new_d1);
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}
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goal state::to_goal() const {
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hypothesis_idx_map<expr> hidx2local;
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metavar_idx_map<expr> midx2meta;
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name M("M");
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std::function<expr(expr const &)> convert = [&](expr const & e) {
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return lean::replace(e, [&](expr const & e) {
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if (is_href(e)) {
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auto r = hidx2local.find(href_index(e));
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lean_assert(r);
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return some_expr(*r);
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} else if (is_mref(e)) {
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auto r = midx2meta.find(mref_index(e));
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if (r) {
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return some_expr(*r);
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} else {
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metavar_decl const * decl = m_metavar_decls.find(mref_index(e));
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lean_assert(decl);
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buffer<expr> ctx;
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decl->get_assumptions().for_each([&](unsigned hidx) {
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ctx.push_back(*hidx2local.find(hidx));
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});
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expr type = convert(decl->get_type());
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expr new_type = Pi(ctx, type);
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expr new_mvar = lean::mk_metavar(name(M, mref_index(e)), new_type);
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expr new_meta = mk_app(new_mvar, ctx);
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midx2meta.insert(mref_index(e), new_meta);
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return some_expr(new_meta);
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}
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} else {
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return none_expr();
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}
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});
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};
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name H("H");
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hypothesis_idx_buffer hidxs;
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get_sorted_hypotheses(hidxs);
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buffer<expr> hyps;
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for (unsigned hidx : hidxs) {
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hypothesis const * h = get_hypothesis_decl(hidx);
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lean_assert(h);
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// after we add support for let-decls in goals, we must convert back h->get_value() if it is available
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expr new_h = lean::mk_local(name(H, hidx), h->get_name(), convert(h->get_type()), binder_info());
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hidx2local.insert(hidx, new_h);
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hyps.push_back(new_h);
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}
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expr new_target = convert(get_target());
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expr new_mvar_type = Pi(hyps, new_target);
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expr new_mvar = lean::mk_metavar(M, new_mvar_type);
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expr new_meta = mk_app(new_mvar, hyps);
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return goal(new_meta, new_target);
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}
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void state::display(environment const & env, io_state const & ios) const {
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formatter fmt = ios.get_formatter_factory()(env, ios.get_options());
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ios.get_diagnostic_channel() << mk_pair(to_goal().pp(fmt), ios.get_options());
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}
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bool state::has_assigned_uref(level const & l) const {
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if (!has_meta(l))
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return false;
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if (m_uassignment.empty())
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return false;
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bool found = false;
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for_each(l, [&](level const & l) {
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if (!has_meta(l))
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return false; // stop search
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if (found)
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return false; // stop search
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if (is_uref(l) && is_uref_assigned(l)) {
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found = true;
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return false; // stop search
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}
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return true; // continue search
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});
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return found;
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}
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bool state::has_assigned_uref(levels const & ls) const {
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for (level const & l : ls) {
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if (has_assigned_uref(l))
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return true;
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}
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return false;
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}
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bool state::has_assigned_uref_mref(expr const & e) const {
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if (!has_mref(e) && !has_univ_metavar(e))
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return false;
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if (m_eassignment.empty() && m_uassignment.empty())
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return false;
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bool found = false;
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for_each(e, [&](expr const & e, unsigned) {
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if (!has_mref(e) && !has_univ_metavar(e))
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return false; // stop search
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if (found)
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return false; // stop search
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if ((is_mref(e) && is_mref_assigned(e)) ||
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(is_constant(e) && has_assigned_uref(const_levels(e))) ||
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(is_sort(e) && has_assigned_uref(sort_level(e)))) {
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found = true;
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return false; // stop search
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}
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return true; // continue search
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});
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return found;
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}
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level state::instantiate_urefs(level const & l) {
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if (!has_assigned_uref(l))
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return l;
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return replace(l, [&](level const & l) {
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if (!has_meta(l)) {
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return some_level(l);
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} else if (is_uref(l)) {
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level const * v1 = get_uref_assignment(l);
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if (v1) {
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level v2 = instantiate_urefs(*v1);
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if (*v1 != v2) {
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assign_uref(l, v2);
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return some_level(v2);
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} else {
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return some_level(*v1);
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}
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}
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}
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return none_level();
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});
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}
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struct instantiate_urefs_mrefs_fn : public replace_visitor {
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state & m_state;
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level visit_level(level const & l) {
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return m_state.instantiate_urefs(l);
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}
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levels visit_levels(levels const & ls) {
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return map_reuse(ls,
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[&](level const & l) { return visit_level(l); },
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[](level const & l1, level const & l2) { return is_eqp(l1, l2); });
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}
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virtual expr visit_sort(expr const & s) {
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return update_sort(s, visit_level(sort_level(s)));
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}
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virtual expr visit_constant(expr const & c) {
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return update_constant(c, visit_levels(const_levels(c)));
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}
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virtual expr visit_local(expr const & e) {
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if (is_href(e)) {
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return e;
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} else {
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return update_mlocal(e, visit(mlocal_type(e)));
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}
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}
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virtual expr visit_meta(expr const & m) {
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lean_assert(is_mref(m));
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if (auto v1 = m_state.get_mref_assignment(m)) {
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if (!has_mref(*v1)) {
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return *v1;
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} else {
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expr v2 = m_state.instantiate_urefs_mrefs(*v1);
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if (v2 != *v1)
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m_state.assign_mref(m, v2);
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return v2;
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}
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} else {
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return m;
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}
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}
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virtual expr visit_app(expr const & e) {
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buffer<expr> args;
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expr const & f = get_app_rev_args(e, args);
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if (is_mref(f)) {
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if (auto v = m_state.get_mref_assignment(f)) {
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expr new_app = apply_beta(*v, args.size(), args.data());
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if (has_mref(new_app))
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return visit(new_app);
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else
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return new_app;
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}
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}
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expr new_f = visit(f);
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buffer<expr> new_args;
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bool modified = !is_eqp(new_f, f);
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for (expr const & arg : args) {
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expr new_arg = visit(arg);
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if (!is_eqp(arg, new_arg))
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modified = true;
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new_args.push_back(new_arg);
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}
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if (!modified)
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return e;
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else
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return mk_rev_app(new_f, new_args, e.get_tag());
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}
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virtual expr visit_macro(expr const & e) {
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lean_assert(is_macro(e));
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buffer<expr> new_args;
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for (unsigned i = 0; i < macro_num_args(e); i++)
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new_args.push_back(visit(macro_arg(e, i)));
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return update_macro(e, new_args.size(), new_args.data());
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}
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virtual expr visit(expr const & e) {
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if (!has_mref(e) && !has_univ_metavar(e))
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return e;
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else
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return replace_visitor::visit(e);
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}
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public:
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instantiate_urefs_mrefs_fn(state & s):m_state(s) {}
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expr operator()(expr const & e) { return visit(e); }
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};
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expr state::instantiate_urefs_mrefs(expr const & e) {
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if (!has_assigned_uref_mref(e))
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return e;
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else
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return instantiate_urefs_mrefs_fn(*this)(e);
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}
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#ifdef LEAN_DEBUG
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bool state::check_hypothesis(expr const & e, unsigned hidx, hypothesis const & h) const {
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lean_assert(closed(e));
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for_each(e, [&](expr const & n, unsigned) {
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if (is_href(n)) {
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lean_assert(h.depends_on(n));
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lean_assert(hidx_depends_on(hidx, href_index(n)));
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} else if (is_mref(n)) {
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// metavariable is in the set of used metavariables
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lean_assert(has_mvar(n));
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}
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return true;
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});
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return true;
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}
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bool state::check_hypothesis(unsigned hidx, hypothesis const & h) const {
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lean_assert(check_hypothesis(h.get_type(), hidx, h));
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lean_assert(h.is_assumption() || check_hypothesis(*h.get_value(), hidx, h));
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return true;
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}
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bool state::check_target() const {
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lean_assert(closed(get_target()));
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for_each(get_target(), [&](expr const & n, unsigned) {
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if (is_href(n)) {
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lean_assert(target_depends_on(n));
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} else if (is_mref(n)) {
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// metavariable is in the set of used metavariables
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lean_assert(has_mvar(n));
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}
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return true;
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});
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return true;
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}
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bool state::check_invariant() const {
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for_each_hypothesis([&](unsigned hidx, hypothesis const & h) {
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lean_assert(check_hypothesis(b, hidx, h));
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});
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lean_assert(check_target());
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return true;
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}
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#endif
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struct hypothesis_dep_depth_lt {
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state const & m_state;
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hypothesis_dep_depth_lt(state const & s): m_state(s) {}
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bool operator()(unsigned hidx1, unsigned hidx2) const {
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hypothesis const * h1 = m_state.get_hypothesis_decl(hidx1);
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hypothesis const * h2 = m_state.get_hypothesis_decl(hidx2);
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return
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h1 && h2 && h1->get_dep_depth() < h2->get_dep_depth() &&
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(h1->get_dep_depth() == h2->get_dep_depth() && hidx1 < hidx2);
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}
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};
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void state::get_sorted_hypotheses(hypothesis_idx_buffer & r) const {
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m_branch.m_hyp_decls.for_each([&](unsigned hidx, hypothesis const &) {
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r.push_back(hidx);
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});
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std::sort(r.begin(), r.end(), hypothesis_dep_depth_lt(*this));
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}
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void state::add_forward_dep(unsigned hidx_user, unsigned hidx_provider) {
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if (auto s = m_branch.m_forward_deps.find(hidx_provider)) {
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if (!s->contains(hidx_user)) {
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hypothesis_idx_set new_s(*s);
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new_s.insert(hidx_user);
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m_branch.m_forward_deps.insert(hidx_provider, new_s);
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}
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} else {
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hypothesis_idx_set new_s;
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new_s.insert(hidx_user);
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m_branch.m_forward_deps.insert(hidx_provider, new_s);
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}
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}
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void state::add_deps(expr const & e, hypothesis & h_user, unsigned hidx_user) {
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if (!has_href(e) && !has_mref(e))
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return; // nothing to be done
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for_each(e, [&](expr const & l, unsigned) {
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if (!has_href(l) && !has_mref(l)) {
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return false;
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} else if (is_href(l)) {
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unsigned hidx_provider = href_index(l);
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hypothesis const * h_provider = get_hypothesis_decl(hidx_provider);
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lean_assert(h_provider);
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if (h_user.m_dep_depth <= h_provider->m_dep_depth)
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h_user.m_dep_depth = h_provider->m_dep_depth + 1;
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if (!h_user.m_deps.contains(hidx_provider)) {
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h_user.m_deps.insert(hidx_provider);
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add_forward_dep(hidx_user, hidx_provider);
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}
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return false;
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} else {
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return true;
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}
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});
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}
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void state::add_deps(hypothesis & h_user, unsigned hidx_user) {
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add_deps(h_user.m_type, h_user, hidx_user);
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if (!h_user.is_assumption()) {
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add_deps(*h_user.m_value, h_user, hidx_user);
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}
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}
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double state::compute_weight(unsigned hidx, expr const & /* type */) {
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// TODO(Leo): use heuristics and machine learning for computing the weight of a new hypothesis
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return 1.0 / (static_cast<double>(hidx) + 1.0);
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}
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expr state::mk_hypothesis(unsigned new_hidx, name const & n, expr const & type, optional<expr> const & value) {
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hypothesis new_h;
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expr r = mk_href(new_hidx);
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new_h.m_name = n;
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new_h.m_type = type;
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new_h.m_value = value;
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new_h.m_self = r;
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new_h.m_proof_depth = m_proof_depth;
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add_deps(new_h, new_hidx);
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m_branch.m_hyp_decls.insert(new_hidx, new_h);
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if (new_h.is_assumption())
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m_branch.m_assumption.insert(new_hidx);
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double w = compute_weight(new_hidx, type);
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m_branch.m_todo_queue.insert(w, new_hidx);
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return r;
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}
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expr state::mk_hypothesis(name const & n, expr const & type, expr const & value) {
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return mk_hypothesis(mk_href_idx(), n, type, some_expr(value));
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}
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expr state::mk_hypothesis(expr const & type, expr const & value) {
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unsigned hidx = mk_href_idx();
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return mk_hypothesis(hidx, name(*g_prefix, hidx), type, some_expr(value));
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}
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expr state::mk_hypothesis(name const & n, expr const & type) {
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return mk_hypothesis(mk_href_idx(), n, type, none_expr());
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}
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expr state::mk_hypothesis(expr const & type) {
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unsigned hidx = mk_href_idx();
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return mk_hypothesis(hidx, name(*g_prefix, hidx), type, none_expr());
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}
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static optional<head_index> to_head_index(expr type) {
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is_not(type, type);
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expr const & f = get_app_fn(type);
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if (is_constant(f) || is_local(f))
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return optional<head_index>(head_index(f));
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else
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return optional<head_index>();
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}
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static optional<head_index> to_head_index(hypothesis const & h) {
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return to_head_index(h.get_type());
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}
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list<hypothesis_idx> state::get_occurrences_of(head_index const & h) const {
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if (auto r = m_branch.m_head_to_hyps.find(h))
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return *r;
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else
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return list<hypothesis_idx>();
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}
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list<hypothesis_idx> state::get_head_related(hypothesis_idx hidx) const {
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hypothesis const * h = get_hypothesis_decl(hidx);
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lean_assert(h);
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/* update m_head_to_hyps */
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if (auto i = to_head_index(*h))
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return get_occurrences_of(*i);
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else
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return list<hypothesis_idx>();
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}
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list<hypothesis_idx> state::get_head_related() const {
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if (auto i = to_head_index(m_branch.m_target))
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return get_occurrences_of(*i);
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else
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return list<hypothesis_idx>();
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}
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|
|
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void state::update_indices(hypothesis_idx hidx) {
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hypothesis const * h = get_hypothesis_decl(hidx);
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lean_assert(h);
|
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/* update m_head_to_hyps */
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if (auto i = to_head_index(*h))
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|
m_branch.m_head_to_hyps.insert(*i, hidx);
|
|
/* TODO(Leo): update congruence closure indices */
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|
}
|
|
|
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optional<unsigned> state::activate_hypothesis() {
|
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if (m_branch.m_todo_queue.empty()) {
|
|
return optional<unsigned>();
|
|
} else {
|
|
unsigned hidx = m_branch.m_todo_queue.erase_min();
|
|
m_branch.m_active.insert(hidx);
|
|
update_indices(hidx);
|
|
return optional<unsigned>(hidx);
|
|
}
|
|
}
|
|
|
|
bool state::hidx_depends_on(unsigned hidx_user, unsigned hidx_provider) const {
|
|
if (auto s = m_branch.m_forward_deps.find(hidx_provider)) {
|
|
return s->contains(hidx_user);
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
void state::set_target(expr const & t) {
|
|
m_branch.m_target = t;
|
|
m_branch.m_target_deps.clear();
|
|
if (has_href(t) || has_mref(t)) {
|
|
for_each(t, [&](expr const & e, unsigned) {
|
|
if (!has_href(e) && !has_mref(e)) {
|
|
return false;
|
|
} else if (is_href(e)) {
|
|
m_branch.m_target_deps.insert(href_index(e));
|
|
return false;
|
|
} else {
|
|
return true;
|
|
}
|
|
});
|
|
}
|
|
}
|
|
|
|
struct expand_hrefs_fn : public replace_visitor {
|
|
state const & m_state;
|
|
list<expr> const & m_hrefs;
|
|
|
|
expand_hrefs_fn(state const & s, list<expr> const & hrefs):
|
|
m_state(s), m_hrefs(hrefs) {}
|
|
|
|
virtual expr visit_local(expr const & e) {
|
|
if (is_href(e) && std::find(m_hrefs.begin(), m_hrefs.end(), e) != m_hrefs.end()) {
|
|
hypothesis const * h = m_state.get_hypothesis_decl(e);
|
|
if (h->get_value()) {
|
|
return visit(*h->get_value());
|
|
}
|
|
}
|
|
return replace_visitor::visit_local(e);
|
|
}
|
|
};
|
|
|
|
expr state::expand_hrefs(expr const & e, list<expr> const & hrefs) const {
|
|
return expand_hrefs_fn(*this, hrefs)(e);
|
|
}
|
|
|
|
auto state::save_assignment() -> assignment_snapshot {
|
|
return assignment_snapshot(m_uassignment, m_metavar_decls, m_eassignment);
|
|
}
|
|
|
|
void state::restore_assignment(assignment_snapshot const & s) {
|
|
std::tie(m_uassignment, m_metavar_decls, m_eassignment) = s;
|
|
}
|
|
|
|
expr state::mk_binding(bool is_lambda, unsigned num, expr const * hrefs, expr const & b) const {
|
|
expr r = abstract_locals(b, num, hrefs);
|
|
unsigned i = num;
|
|
while (i > 0) {
|
|
--i;
|
|
expr const & h = hrefs[i];
|
|
lean_assert(is_href(h));
|
|
hypothesis const * hdecl = get_hypothesis_decl(h);
|
|
lean_assert(hdecl);
|
|
expr t = abstract_locals(hdecl->get_type(), i, hrefs);
|
|
if (is_lambda)
|
|
r = ::lean::mk_lambda(hdecl->get_name(), t, r);
|
|
else
|
|
r = ::lean::mk_pi(hdecl->get_name(), t, r);
|
|
}
|
|
return r;
|
|
}
|
|
|
|
expr state::mk_lambda(list<expr> const & hrefs, expr const & b) const {
|
|
buffer<expr> tmp;
|
|
to_buffer(hrefs, tmp);
|
|
return mk_lambda(tmp, b);
|
|
}
|
|
|
|
expr state::mk_pi(list<expr> const & hrefs, expr const & b) const {
|
|
buffer<expr> tmp;
|
|
to_buffer(hrefs, tmp);
|
|
return mk_pi(tmp, b);
|
|
}
|
|
|
|
void initialize_state() {
|
|
g_prefix = new name(name::mk_internal_unique_name());
|
|
}
|
|
|
|
void finalize_state() {
|
|
delete g_prefix;
|
|
}
|
|
}}
|