lean2/src/library/blast/intros_action.cpp

57 lines
1.7 KiB
C++

/*
Copyright (c) 2015 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <limits>
#include "kernel/abstract.h"
#include "kernel/instantiate.h"
#include "library/blast/blast.h"
#include "library/blast/proof_expr.h"
namespace lean {
namespace blast {
struct intros_proof_step_cell : public proof_step_cell {
list<expr> m_new_hs;
virtual ~intros_proof_step_cell() {}
virtual action_result resolve(expr const & pr) const {
expr new_pr = mk_proof_lambda(curr_state(), m_new_hs, pr);
return action_result::solved(new_pr);
}
virtual bool is_silent() const override { return true; }
};
bool intros_action(unsigned max) {
if (max == 0)
return true;
state & s = curr_state();
expr target = whnf(s.get_target());
if (!is_pi(target))
return false;
auto pcell = new intros_proof_step_cell();
s.push_proof_step(pcell);
buffer<expr> new_hs;
for (unsigned i = 0; i < max; i++) {
if (!is_pi(target))
break;
expr href;
expr htype = head_beta_reduce(binding_domain(target));
if (is_default_var_name(binding_name(target)) && closed(binding_body(target))) {
href = s.mk_hypothesis(htype);
} else {
href = s.mk_hypothesis(binding_name(target), htype);
}
new_hs.push_back(href);
target = whnf(instantiate(binding_body(target), href));
}
pcell->m_new_hs = to_list(new_hs);
s.set_target(target);
return true;
}
bool intros_action() {
return intros_action(std::numeric_limits<unsigned>::max());
}
}}