121 lines
5.2 KiB
C++
121 lines
5.2 KiB
C++
/*
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Copyright (c) 2014 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 "library/constants.h"
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#include "kernel/abstract.h"
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#include "kernel/instantiate.h"
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#include "kernel/kernel_exception.h"
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#include "library/reducible.h"
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#include "library/util.h"
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#include "library/tactic/elaborate.h"
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#include "library/tactic/expr_to_tactic.h"
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namespace lean {
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expr mk_generalize_tactic_expr(expr const & e, name const & id) {
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return mk_app(mk_constant(get_tactic_generalize_tac_name()),
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e, mk_constant(id));
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}
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optional<proof_state> generalize_core(environment const & env, io_state const & ios, elaborate_fn const & elab,
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expr const & e, name const & x, proof_state const & s, name const & tac_name,
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bool intro) {
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proof_state new_s = s;
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if (auto new_e = elaborate_with_respect_to(env, ios, elab, new_s, e)) {
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name_generator ngen = new_s.get_ngen();
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substitution subst = new_s.get_subst();
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goals const & gs = new_s.get_goals();
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goal const & g = head(gs);
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auto tc = mk_type_checker(env, ngen.mk_child());
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auto e_t_cs = tc->infer(*new_e);
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if (e_t_cs.second) {
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throw_tactic_exception_if_enabled(s, sstream() << "invalid '" << tac_name << "' tactic, unification constraints "
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"have been generated when inferring type");
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return none_proof_state(); // constraints were generated
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}
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expr e_t = e_t_cs.first;
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expr t = subst.instantiate(g.get_type());
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name n;
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if (is_constant(e))
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n = const_name(e);
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else if (is_local(e))
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n = local_pp_name(e);
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else
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n = x;
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expr new_t, new_m, new_val;
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expr to_check;
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if (intro) {
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buffer<expr> hyps;
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g.get_hyps(hyps);
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expr new_h = mk_local(ngen.next(), get_unused_name(x, hyps), e_t, binder_info());
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new_t = instantiate(abstract(t, *new_e), new_h);
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to_check = Pi(new_h, new_t);
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new_m = mk_metavar(ngen.next(), Pi(hyps, Pi(new_h, new_t)));
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new_m = mk_app(new_m, hyps);
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new_val = mk_app(new_m, *new_e);
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new_m = mk_app(new_m, new_h);
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} else {
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new_t = mk_pi(n, e_t, abstract(t, *new_e));
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to_check = new_t;
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new_m = g.mk_meta(ngen.next(), new_t);
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new_val = mk_app(new_m, *new_e);
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}
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try {
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check_term(*tc, g.abstract(to_check));
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} catch (kernel_exception const & ex) {
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std::shared_ptr<kernel_exception> ex_ptr(static_cast<kernel_exception*>(ex.clone()));
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throw_tactic_exception_if_enabled(s, [=](formatter const & fmt) {
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format r = format("invalid '") + format(tac_name) + format("' tactic, type error");
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r += line();
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r += ex_ptr->pp(fmt);
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return r;
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});
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return none_proof_state();
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}
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assign(subst, g, new_val);
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goal new_g(new_m, new_t);
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return some(proof_state(new_s, goals(new_g, tail(gs)), subst, ngen));
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}
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return none_proof_state();
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}
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optional<proof_state> generalize(environment const & env, io_state const & ios, elaborate_fn const & elab,
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expr const & e, name const & x, proof_state const & s) {
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return generalize_core(env, ios, elab, e, x, s, "generalize", false);
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}
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tactic generalize_tactic(elaborate_fn const & elab, expr const & e, name const & x) {
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return tactic01([=](environment const & env, io_state const & ios, proof_state const & s) {
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return generalize(env, ios, elab, e, x, s);
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});
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}
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void initialize_generalize_tactic() {
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register_tac(get_tactic_generalize_tac_name(),
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[](type_checker &, elaborate_fn const & fn, expr const & e, pos_info_provider const *) {
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check_tactic_expr(app_arg(app_fn(e)), "invalid 'generalize' tactic, invalid argument");
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name id = tactic_expr_to_id(app_arg(e), "invalid 'generalize' tactic, argument must be an identifier");
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return generalize_tactic(fn, get_tactic_expr_expr(app_arg(app_fn(e))), id);
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});
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register_tac(get_tactic_generalizes_name(),
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[](type_checker &, elaborate_fn const & fn, expr const & e, pos_info_provider const *) {
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buffer<expr> args;
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get_tactic_expr_list_elements(app_arg(e), args, "invalid 'generalizes' tactic, list of expressions expected");
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if (args.empty())
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return id_tactic();
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tactic r = generalize_tactic(fn, args.back(), "x");
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args.pop_back();
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while (!args.empty()) {
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r = then(generalize_tactic(fn, args.back(), "x"), r);
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args.pop_back();
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}
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return r;
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});
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}
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void finalize_generalize_tactic() {
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}
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}
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